STAT 222 Module 8 QA.pdf

# Chapter 104 exercise question 04 using foot length

• Homework Help
• 73

This preview shows pages 38–41. Sign up to view the full content.

make up the null distribution. Chapter 10.4 Exercise Question 04 Using foot length and height data, we shuffled the -values 100 times and each time plotted the resulting regression line in the graph shown for Exercise 10.4.4. The regression line for the observed data is the one being pointed at with the dashed arrow. Based on the plot of these lines, what can you say about the p-value if we are testing to see whether there is a positive association between height and foot length? Explain. Chapter 10.4 Exercise Question 05 Height and leap Suppose you are testing to see if there is an association between a person's height and their vertical leap. You've collected data on this from 20 people. Describe how you would construct a null distribution for this situation by hand using the slope of the regression line as your statistic. Assume you have 20 slips of paper containing the 20 heights and 20 slips of paper containing the 20 vertical leap distances. Lay the 20 slips of paper with the heights written on them in a line on a flat surface. Shuffle the 20 slips of paper with the vertical leap distances on them and deal one out to each of the 20 slips of paper with the heights on them. Calculate the least squares regression equation for these 20

This preview has intentionally blurred sections. Sign up to view the full version.

pairs of data and record the slope. Repeat this procedure 1,000 times to get 1,000 simulated slopes which make up the null distribution. Chapter 10.4 Exercise Question 06 Textbook prices A random sample of 15 textbooks in a campus bookstore was selected. Two of the variables recorded were the price of the book (in dollars) and the number of pages it contained. The data are displayed in the following scatterplot. Summarize the form, direction and strength of association of the scatterplot for Exercise 10.4.6. Chapter 10.4 Exercise Question 07 Refer to the data in the previous exercise. State the null and alternative hypotheses for a test of possible association between pages and price. The null distribution for Exercise 10.4.7 was created to test the hypotheses stated in the previous question using slope as the statistic.
i.Based on information shown in the null distribution, how many standard deviations is our observed statistic above the mean of the null distribution? (That is, what is the standardized statistic?) ii.Based on your standardized statistic, do you have strong evidence of an association between number of pages and price of textbooks? Explain. Chapter 10.4 Exercise Question 08 Reconsider the previous two exercises about textbook prices. The equation of the least squares regression line for predicting price from number of pages is prıce \ = 14.11 + 0.13 (pages). Interpret what the slope coefficient means in the context of pages and price. Interpret the intercept. Is this an example of extrapolation? Why or why not? Chapter 10.4 Exercise Question 09 Sleep and maze performance Student researchers asked their subjects how much sleep they had the previous night (in hours) and then timed how long it took them (in seconds) to complete a paper and pencil maze. The results are shown in the scatterplot along with the regression line.

This preview has intentionally blurred sections. Sign up to view the full version.

This is the end of the preview. Sign up to access the rest of the document.
• Summer '18
• Null hypothesis, Statistical hypothesis testing, Correlation and dependence, Pearson product-moment correlation coefficient

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern