Category: Statistics

Which of the following is/are true about confidence intervals (choose one or more)
Group of answer choices
when we calculate a 95% confidence interval there is statistical significance
knowing the range of a parameter is more accurate than a point estimate
confidence interval of the mean = mean +/- a margin of error using a constant
confidence intervals are abbreviated CI
Flag question: Question 2
Question 21.25 pts
The constant used in calculating the 99% confidence interval in the proportion formula is:
Group of answer choices
1.645
1.96
3.54
2.576
Flag question: Question 3
Question 31.25 pts
If you use the Excel Data Analysis Tools to calculate the descriptive statistics and check the box “confidence level for mean” what do you do with this number to obtain the confidence interval? (choose one or more)
Group of answer choices
do nothing – this number is the conficence interval
use this value to calculate the lower and upper bound of the interval
add and subtract this value from the median
add and subtract this value to the mean
Flag question: Question 4
Question 41.25 pts
Why do we need confidence intervals? (choose one or more)
Group of answer choices
To express statistical uncertainty
To accurately state a range of a population parameter
To give insight about the magnitude of the effect
To tell us the chance (95%) of a particular outcome
Flag question: Question 5
Question 51.25 pts
When calculating  confidence intervals in this class the product of a constant times a margin of error is added and subtracted to what value to obtain the CI range?
Group of answer choices
median
standard deviation
alpha
mean
Flag question: Question 6
Question 61.25 pts
The average BMI for a sample of 10 preschoolers is 16.3, with a standard deviation of 1.4. What is the 90% confidence interval for the BMI of all preschoolers? (round to two decimal places)
Group of answer choices
(15.57, 17.03)
(15.29, 16.91)
(15.3, 17.3)
(15.49, 17.11)
Flag question: Question 7
Question 71.25 pts
When calculating the 99% confidence interval of the mean for a sample of 15 patients, what constant is used in the formula?
Group of answer choices
2.603
2.947
2.625
2.977
Flag question: Question 8
Question 81.25 pts
What affects the width of a confidence interval? (choose one or more)
Group of answer choices
Our desired confidence level.
Median of the sample
Sample size.
Variation within the population.
Flag question: Question 9
Question 91.25 pts
What is the constant used to calculate the 90% confidence interval of the mean when n=50?
Group of answer choices
2.576
1.645
1.96
Flag question: Question 10
Question 101.25 pts
If df=22, what constant do we use to calculate the 90% confidence interval of the mean?
Group of answer choices
1.321
1.717
1.714
1.323
Flag question: Question 11
Question 111.25 pts
If n=15, what constant do we use to calculate the 95% confidence interval of the mean?
Group of answer choices
1.762
2.132
2.145
1.753
Flag question: Question 12
Question 121.25 pts
As you increase your confidence level, what happens to the width of the confidence interval?
Group of answer choices
It stays the same.
It gets higher.
It gets narrower.
It gets wider.
Flag question: Question 13
Question 131.25 pts
When would you use the confidence interval formula for a proportion? (choose one or more)
Group of answer choices
You have summary information as a percentage or survey sample data
You do not know the standard deviation
Your sample size is under 30
To determine if the groups are significantly different
Flag question: Question 14
Question 141.25 pts
If in a sample of 355 adult males, we have a mean total cholesterol level of 185 mg, with s = 16. What is the 99% confidence interval for mean total cholesterol level of all males? 
Group of answer choices
(183.6, 186.4)
(183.34, 186.66)
(181.45, 188.37)
(182.81, 187.19)
Flag question: Question 15
Question 151.25 pts
Which of the following is/are true about the Excel function = CONFIDENCE.NORM
Group of answer choices
This is the appropriate function to use to calculate CI of a proportion
This is the appropriate function to use if the sample size is greater than 30
This function uses the normal distribution (table B.1)
This is the appropriate function to use if the sample size is less than 30
Flag question: Question 16
Question 161.25 pts
For a sample with df = 5, what is the t-score constant to calculate a confidence level of 99%? 
Group of answer choices
3.365
2.015
2.571
4.032
Flag question: Question 17
Question 171.25 pts
If n=20, what constant do we use to calculate the 99% confidence interval of the mean?
Group of answer choices
2.086
2.861
2.093
2.846
Flag question: Question 18
Question 181.25 pts
For a sample with df = 5, what is the t-score constant to calculate a confidence level of 95%? 
Group of answer choices
1.943
2.571
1.476
2.015
Flag question: Question 19
Question 191.25 pts
Researchers find that the 95% confidence interval for women’s systolic blood pressure is (126.67, 127.93). How do you interpret this finding?
Group of answer choices
We are 95% confident that the true mean for women’s systolic blood pressure is between 126.67 and 127.93.
All of the above.
There is a 95% chance that the true mean for women’s systolic blood pressure is between 126.67 and 127.93.
95% of the data values for women’s systolic blood pressure are between 126.67 and 127.93.
Flag question: Question 20
Question 201.25 pts
In a randomly selected sample of 500 Phoenix residents, 445 supported mandatory sick leave for food handlers. Legislators want to be very confident that voters will support this issue before drafting a bill. What is the 99% confidence interval for the percentage of Phoenix residents who support mandatory sick leave for food handlers?
Group of answer choices
(86.7%, 91.3%)
(86.26%, 91.74%)
(85.4%, 92.6%)
There is not enough information to determine CI

First, open this data file from within Jamovi. It contains data from a project on math anxiety and other variables. Here is the codebook for this data set (the codebook contains information about each variable and what it means, along with specific questions participants were asked and their response options). 
After opening the data set, locate the variables that relate to trait anxiety (STICSA – Trait). If you look at the codebook, these variables are Q9.1_1 through Q9.1_21, but they have two subscales: somatic (refers to the bodily experiences of anxiety) and cognitive (refers to mental experiences of anxiety). Find the questions that are on each subscale and compute a mean for each. There will be no reverse-coding.
Next:
1. Determine whether there is a correlation between these two subscales of the STICSA.
2. Produce a scatterplot.
3. Report the results in APA styLE 

Lab Assignment
The
highlight of this week’s lab is confidence intervals and the use of these
intervals in the health sciences. A short reading specifically relates
confidence intervals to health sciences. Then, you are asked to demonstrate
your knowledge of confidence intervals by practically applying them.
Step 1:
Use the two articles attached
step 2:
Consider using confidence intervals in health sciences with these articles as
inspiration and insights. (Articles attached)
Step 3:
Use the data collected below the Excel spreadsheet for the Week 5 Lab (heights
of 20 different people that you work. discuss
Using data collected above
the heights of 20 people, The participants of this study were selected using a
simple random sampling technique
·       Your
method of collecting the values that you are using in your study is simple random.
·        What are some faults with this type of data
collection?
·       What
other types of data collection could you have used, and how might this have
affected your study?
·       Write
a paragraph summarizing what you learned from the articles provided.  Consider the use of confidence intervals in
health sciences with these articles as inspiration and insights
Step 4:
Now, use the Week 6 Spreadsheet to help you calculate the following
questions/statements.
a)     Give
a point estimate (mean) for the average height of all people at your workplace.
Start by putting the 20 heights you are working with into the blue Data column
of the spreadsheet. What is your point estimate, and what does this mean? Example of exel
b)    
Find a 95% confidence interval for the
true mean height of all the people at your place of work. What is the interval?
[see screenshot below]
c)    
c)
Give a practical interpretation of the interval you found in part b, and
explain carefully what the output means. (For example, you might say, “I
am 95% confident that the true mean height of all of the people in my company
is between 64 and 68 inches”).
d) Post a screenshot of your work from
the t value Confidence Interval for µ from the Confidence Interval tab on the
Week 6 Excel spreadsheet attached , Example of excel
[O1] 
Step 5:
Now, change your confidence level to 99% for the same data, and post a
screenshot of this table, as well.
·      
Give a practical interpretation of the 99%
confidence interval (Write a complete sentence)
Example of Excel
Step 6:
Compare the margins of error from the two screenshots. Would the margin of
error be larger or smaller for the 99% CI? Explain your reasoning
·      
Would the margin of error be larger or
smaller for the 99% CI?
·      
Explain your reasoning. As the confidence
level increases, what happens to the Margin of Error?
Requirements
•           Length:2 page
•           1-inch margins
•           Double spaced
•           12-point Times New Roman font
•           APA format for in-text citations: Cite
the two articles.
•           Minimum of 2 scholarly sources
•           Chapter 2
-https://openstax.org/books/introductory-business-statistics/pages/1-1-definitions-of-statistics-probability-and-key-terms
[O1]

I have done the first 3 questions needed for the homework. I have 2 more left. 
Attached the screenshots for the questions. I need 14.21 and 14.35 be done please.
Exercise 14.3 is done and you will be able to see in the spreadsheet – you will need it for exercise 14.21.

You have a sample of 45 males, with an age range of 15-19, a mean height of 70.8 inches and a s of 1.5 inches.  What is the standard error of the mean?
Group of answer choices
1.5
1.34
0.2236
0.0333
Flag question: Question 2
Question 21.25 pts
Okunrintemi, V. et al (2019). Trends and costs associated with suboptimal physical activity among US women with cardiovascular disease. Jama Network Open 2(4):e191977
These data are based upon a nationally representative survey spanning 10 years.  Odds ratios were adjusted (a statistical term meaning to remove effects of different variables) but we still interpret them in the same way as you learned in the module.  
For each variable (i.e. age, income strata, race/ethnicity, health insurance…) the first group has an odds ratio of 1.  Why is that?  Why is there a group with on odds ratio of 1 within each variable?
Group of answer choices
No answer text provided.
The other groups are being compared to this group. The first group of each variable is the reference group.
The first group has no risk of disease based upon the exposure.
The first group (i.e. 18-39 year olds, high income, non-Hispanic white…) has the lowest risk of disease.
Flag question: Question 3
Question 31.25 pts
Which of the following are assumptions of a one-sample test?  (choose one or more)
Group of answer choices
normal distribution of data
ordinal or nominal scale of measurement
Interval or ratio scale of measurement
random sampling or selection
Flag question: Question 4
Question 41.25 pts
What is the Excel function for a one-sample z-test?
Group of answer choices
STANDARDIZE
ONE.SMPL 
T.TEST
Z.TEST
Flag question: Question 5
Question 51.25 pts
A ________ is a statistic that measures the magnitude of the relationship between variables.
Group of answer choices
t-test
Measure of effect
p-value
Confounder
Flag question: Question 6
Question 61.25 pts
In the United States, mothers who live in poverty generally have babies with lower birthweight than women who do not live in poverty. The average birthweight for women living in poverty is 2800 grams, with a standard deviation of 500. Recently, a local hospital introduced an innovative prenatal care program to reduce the number of low birthweight babies born in the hospital. In the first year, 35 mothers, all of whom live in poverty, participated in this program. Program evaluators want to determine if the birthweight for infants of women who participated in the program is greater than the average birthweight for women who live in poverty. They choose an α of 0.05. The following data is the birthweight in grams for the babies born to the mothers who participated in this program.
3550
2700
2425
2900
3100
3300
3075
2850
3150
2550
3500
2600
2300
3450
3100
3275
2600
3200
3250
2450
3350
3350
2725
3200
2600
3250
3400
2975
3425
2975
3450
3250
3125
2750
2600
Use the provided information and data to run a one-sample z-test in Excel.
05-8 Data_homework7-1.xlsxDownload 05-8 Data_homework7-1.xlsx
How would you write the null hypothesis?
Group of answer choices
H0: xbar  2800
Flag question: Question 7
Question 71.25 pts
The average birthweight for babies in the United States is 3,325 grams with σ = 525.  A researcher wishes to test whether or not a sample of 250 women in a rural community have a significantly different average birthweight than the national average at the α = 0.05 level. The mean birthweight for the sample of women in the rural community is 3400 grams.
What is the degrees of freedom for this study?
Group of answer choices
249
500
250
125
Flag question: Question 8
Question 81.25 pts
For which of the following scenarios would it be appropriate to use a one-sample z-test? (choose one or more)
Group of answer choices
Comparing the number of packs of cigarettes smoked per day by a sample of rural residents with the number of cigarettes smoked per day by all persons in the USA
Comparing the average weight of newborns in Hospital A to the average weight of newborns in Hospital B
Comparing political affiliation scores (ranging from 0-20) of ASU students against the political affiliation scores of all college students
Comparing the results of Likert scale patient satisfaction scores of patients at the Veterans Administration against the Likert scale patient satisfaction scores of the overall population of patients (non-VA patients)
Flag question: Question 9
Question 91.25 pts
The average birthweight for babies in the United States is 3,325 grams with σ = 525.  A researcher wishes to test whether or not a sample of 250 women in a rural community have a significantly different average birthweight than the national average at the α = 0.05 level. The mean birthweight for the sample of women in the rural community is 3400 grams. After calculating the test statistic from the  answer the following question:
True or False: this finding is statistically significant.
Group of answer choices
True
False
Flag question: Question 10
Question 101.25 pts
Okunrintemi, V. et al (2019). Trends and costs associated with suboptimal physical activity among US women with cardiovascular disease. Jama Network Open 2(4):e191977
These data are based upon a nationally representative survey spanning 10 years.  Odds ratios were adjusted (a statistical term meaning to remove effects of different variables) but we still interpret them in the same way as you learned in the module.  
Which of the following is the best interpretation of the odds ratio of 1.29 among low income strata women?
Group of answer choices
High income women with CVD have a 1.29 odds of engaging in suboptimal physical activity.
The odds of women with CVD engaging in suboptimal physical activity is 1.29 times greater in low income women as compared to high income women.
Low income women have a 129% greater chance of developing CVD.
There is no significant difference between high income women and low income women with CVD and their suboptimal physical activity.
Flag question: Question 11
Question 111.25 pts
In the United States, mothers who live in poverty generally have babies with lower birthweight than women who do not live in poverty. The average birthweight for women living in poverty is 2800 grams, with a standard deviation of 500. Recently, a local hospital introduced an innovative prenatal care program to reduce the number of low birthweight babies born in the hospital. In the first year, 35 mothers, all of whom live in poverty, participated in this program. Program evaluators want to determine if the birthweight for infants of women who participated in the program is greater than the average birthweight for women who live in poverty. They choose an α of 0.05. The following data is the birthweight in grams for the babies born to the mothers who participated in this program.
3550
2700
2425
2900
3100
3300
3075
2850
3150
2550
3500
2600
2300
3450
3100
3275
2600
3200
3250
2450
3350
3350
2725
3200
2600
3250
3400
2975
3425
2975
3450
3250
3125
2750
2600
Use the provided information and data to run a one-sample z-test in Excel.
05-8 Data_homework7-1.xlsxDownload 05-8 Data_homework7-1.xlsx
What is the p-value for the one-sample z-test?
Group of answer choices
0.0044
2.62
0.523
1.96
Flag question: Question 12
Question 121.25 pts
The purpose of the one-sample test is: (choose one or more)
Group of answer choices
To examine the difference between one sample and a population
Determine the probability that a sample and population are the same with respect to a particular variable
Compare a sample and population on a variable that is interval/ratio in measure
To compare a test statistic to alpha
Flag question: Question 13
Question 131.25 pts
In Excel functions, what does the output from the one-sample z-test represent?
Group of answer choices
The one-tailed probability value (p-value)
The significance level (alpha)
The obtained value
The critical value
Flag question: Question 14
Question 141.25 pts
Okunrintemi, V. et al (2019). Trends and costs associated with suboptimal physical activity among US women with cardiovascular disease. Jama Network Open 2(4):e191977
These data are based upon a nationally representative survey spanning 10 years.  Odds ratios were adjusted (a statistical term meaning to remove effects of different variables) but we still interpret them in the same way as you learned in the module.  
Which of the following odds ratios are significant at alpha = 0.05?  (select all that apply)
Group of answer choices
1.33 among Hispanic women
0.83 among women living in the West
1.07 among women living in the South
0.92 among Asian women
1.22 among African American women
Flag question: Question 15
Question 151.25 pts
Okunrintemi, V. et al (2019). Trends and costs associated with suboptimal physical activity among US women with cardiovascular disease. Jama Network Open 2(4):e191977
These data are based upon a nationally representative survey spanning 10 years.  Odds ratios were adjusted (a statistical term meaning to remove effects of different variables) but we still interpret them in the same way as you learned in the module.  
What is the best interpretation of the odds ratio of 0.81 among participants with some college under the variable education level?
Group of answer choices
There is no significant difference between in suboptimal physical activity among women with CVD based upon education.
High school educated women with CVD have a 0.81 odds of engaging in suboptimal physical activity.
The odds of women with CVD engaging in suboptimal physical activity is 0.81 among women with some college as compared to women without high school education. There is a protective effect of having some college education.
There is a 81% chance of women developing CVD if they have some college.
Flag question: Question 16
Question 161.25 pts
How do we interpret Cohen’s D of .61?
Group of answer choices
small effect
large effect
medium effect
Flag question: Question 17
Question 171.25 pts
In the United States, mothers who live in poverty generally have babies with lower birthweight than women who do not live in poverty. The average birthweight for women living in poverty is 2800 grams, with a standard deviation of 500. Recently, a local hospital introduced an innovative prenatal care program to reduce the number of low birthweight babies born in the hospital. In the first year, 35 mothers, all of whom live in poverty, participated in this program. Program evaluators want to determine if the birthweight for infants of women who participated in the program is greater than the average birthweight for women who live in poverty. They choose an α of 0.05. The following data is the birthweight in grams for the babies born to the mothers who participated in this program.
3550
2700
2425
2900
3100
3300
3075
2850
3150
2550
3500
2600
2300
3450
3100
3275
2600
3200
3250
2450
3350
3350
2725
3200
2600
3250
3400
2975
3425
2975
3450
3250
3125
2750
2600
Use the provided information and data to run a one-sample z-test in Excel.
05-8 Data_homework7-1.xlsxDownload 05-8 Data_homework7-1.xlsx
Use the provided information and data to run a one-sample z-test in Excel.
Based on this information the researcher should make the decision to ___________.
Group of answer choices
change the null hypothesis
reject the null hypothesis
change the alternate hypothesis
fail to reject the null hypothesis
Flag question: Question 18
Question 181.25 pts
In the United States, mothers who live in poverty generally have babies with lower birthweight than women who do not live in poverty. The average birthweight for women living in poverty is 2800 grams, with a standard deviation of 500. Recently, a local hospital introduced an innovative prenatal care program to reduce the number of low birthweight babies born in the hospital. In the first year, 35 mothers, all of whom live in poverty, participated in this program. Program evaluators want to determine if the birthweight for infants of women who participated in the program is greater than the average birthweight for women who live in poverty. They choose an α of 0.05. The following data is the birthweight in grams for the babies born to the mothers who participated in this program.
3550
2700
2425
2900
3100
3300
3075
2850
3150
2550
3500
2600
2300
3450
3100
3275
2600
3200
3250
2450
3350
3350
2725
3200
2600
3250
3400
2975
3425
2975
3450
3250
3125
2750
2600
Use the provided information and data to run a one-sample z-test in Excel.
05-8 Data_homework7-1.xlsxDownload 05-8 Data_homework7-1.xlsx
Use the provided information and data to run a one-sample z-test in Excel.
True or False, this finding is statistically significant (at the  = .05 level).
Group of answer choices
True
False
Flag question: Question 19
Question 191.25 pts
The average birthweight for babies in the United States is 3,325 grams with σ = 525.  A researcher wishes to test whether or not a sample of 250 women in a rural community have a significantly different average birthweight than the national average at the α = 0.05 level. The mean birthweight for the sample of women in the rural community is 3400 grams.
What is the test statistic?
Group of answer choices
-1.35
-0.37
0.14
2.26
Flag question: Question 20
Question 201.25 pts
In the United States, mothers who live in poverty generally have babies with lower birthweight than women who do not live in poverty. The average birthweight for women living in poverty is 2800 grams, with a standard deviation of 500. Recently, a local hospital introduced an innovative prenatal care program to reduce the number of low birthweight babies born in the hospital. In the first year, 35 mothers, all of whom live in poverty, participated in this program. Program evaluators want to determine if the birthweight for infants of women who participated in the program is greater than the average birthweight for women who live in poverty. They choose an α of 0.05. The following data is the birthweight in grams for the babies born to the mothers who participated in this program.
3550
2700
2425
2900
3100
3300
3075
2850
3150
2550
3500
2600
2300
3450
3100
3275
2600
3200
3250
2450
3350
3350
2725
3200
2600
3250
3400
2975
3425
2975
3450
3250
3125
2750
2600
Use the provided information and data to run a one-sample z-test in Excel.
05-8 Data_homework7-1.xlsxDownload 05-8 Data_homework7-1.xlsx
Use the provided information and data to run a one-sample z-test in Excel.
How would you write the alternative hypothesis?
Group of answer choices
Ha: xbar  2800
Ha: xbar = 2800

Answer the three questions and provide all of your work neatly on a piece of paper and send to me. This is required or I will not receive credit. The three problems are shown in the description.

The goal of this discussion board is to apply what you’ve learned to some data sets.
Pick two variables that are worth comparing. You should be able to picture two columns of data for each variables. For instance; if you wanted to compare two soccer teams, you could how many points the teams scored for several different seasons. Look below to see some examples!
Initial post:
1. Make an initial post that gives a brief description of the two variables you’ve chosen.
2. Make parallel box plots for the two columns of data (example below)
3.Calculate the mean, median, and standard deviation (and include them in your post)
Responses:
In your responses to classmates, check out their given information and answer the following:
– What’s the shape of each variable? (Is it symmetric or skewed?)
– What’s a good representation of the center of each variable? (Mean or median?)
-How do the two variables compare with regards to their spread?

Please try to make it as less confusing as possible. Do the problems in steps. For any multiple choice questions you can just simply put  1. B 2. C etc.
For the word problem I’ve uploaded some examplesof order you can write out the solved problems in that way so it’s confusing. The picture files has numbers in their orders as well. 

To access the pages and assignments listed, use Modules in the Left Navigation.
You will be working on the Semester Project throughout the term in parts as Project Part Assignments. Additional information can be found on the Semester Project Information page. You will get feedback from your instructor on the parts of the project in the Project Part as listed. Use that feedback to improve that portion of the project.
Project Part 3: Descriptive Statistics
1) Using the 35 values you created for Project Part 1, you will collect the following Descriptive Statistics using your TI-84 functions and explain what they tell you about your data.
If you did not collect the 35 values yet, review the Template and the Data Sets for Project Parts and the Semester Project page, and collect them now.
2) Click Stat > Line 1 Edit and enter your values into L1.
3) Stat > Calc > Line 1 1-Var Stats, into List enter L1 (use 2nd 1), and then enter to collect the following values:
Mean: use x¯¯¯
x
¯
Standard deviation: Sx (NOT σx)
5 Number Summary: (includes Min through Max at the bottom of the list)
Find the Mode(s) by clicking 2nd mode (to quit) then Stat > Line 2: SortA( enter 2nd 1 enter (for L1 if that is your list name), then 2nd 1 (to pull up L1) and click enter to view the entries in your list
Central Measures List your Mean, Median, and Mode(s) (if more than one Mode list all)
Provide at least 2 quality sentences describing which measure is best for your data and why.
Are these values close to each other, why or why not? 5 Number Summary
List the Minimum, Q1, Median, Q3, Maximum.
Find the IQR, and the Interquartile Range, and show your work. Using at least 2 quality sentences, describe what the 5 Number Summary and IQR tell you about your data. Do you have any outliers, if so what are they? Explain why you choose these as outliers. If you have no outliers explain how you know. Standard Deviation
List your Standard Deviation
Using at least 2 quality sentences, describe what the standard deviation tells you about the spread of your data. Is your data close together, or spread far apart? Explain in your own words. Do you have about 68% of your data within 1 standard deviation from the mean? Explain in your own words. When working on each part of the Semester Project the Best Practice is to type the information onto the appropriate slide of the Template, remove the directions, and then copy and paste your work and results into the text submission area of the assignment.
You may submit the project part as a text submission, Word Document, or PowerPoint Slide from the Template (only that slide!) Do not submit your work as an embedded image in one of those files. Images cannot be accepted for these assignments. (File Types allowed: .doc, .docx, ppt, .pptx)
Note: you will earn at most 10 points. If it is not submitted a 0 will be put in the grade book but it does not lower your grade.

To Prepare
Download and review the GSS Excel Data Set 
Download and review the GSS Codebook.
Choose 1 continuous variable and the first 50 participant responses.
Using Excel complete the following.
Create a grouped frequency distribution table using a continuous variable with the first 50 participant responses from the GSS data set. Use the variable assigned below.
The table should have two columns: the interval and frequency columns (you will make up this table on your own). There should not be more than ten intervals used. Place the table into the discussion board.
From the grouped frequency table, explain why you chose the intervals you did to divide the data.
Analyze how many frequencies you had for each of the intervals in your data.
Explain what your frequency table could tell us about the data collected for this variable.
Assigned variable:  ‘sei10’