Chapter 104 exercise question 04 using foot length

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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
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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.
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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.
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  • Summer '18
  • Null hypothesis, Statistical hypothesis testing, Correlation and dependence, Pearson product-moment correlation coefficient

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