# Answers only (statistics)

See attachment:

**74.** Perform a goodness-of-fit test to determine whether the local results follow the distribution of the U.S. overall student population based on ethnicity

Race/Ethnicity AP Population Overall Student Population Survey Frequency

Asian, Asian American 10.2% 5.4% 113

Black or African-American 8.2% 14.5% 94

Hispanic or Latino 15.5% 15.9% 136

American Indian 0.6% 1.2% 10

White 59.4% 61.6% 604

Not reported/other 6.1% 1.4% 43

**102**. Do men and women select different breakfasts? The breakfasts ordered by randomly selected men and women at a popular breakfast place is shown in Table 11.55. Conduct a test for homogeneity at a 5% level of significance

French Toast Pancakes Waffles Omelettes

Men 47 35 28 53

Women 65 59 55 b 60

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**114**. chi-square test statistic = ________ (look below)

**116.** Graph the situation. Label and scale the horizontal axis. Mark the mean and test statistic. Shade the p-value

Suppose an airline claims that its flights are consistently on time with an average delay of at most 15 minutes. It claims that the average delay is so consistent that the variance is no more than 150 minutes. Doubting the consistency part of the claim, a disgruntled traveler calculates the delays for his next 25 flights. The average delay for those 25 flights is 22 minutes with a standard deviation of 15 minutes.

**76.** The following table shows data on average per capita wine consumption and heart disease rate in a random sample of 10 countries.

Yearly wine consumption in liters 2.5 3.9 2.9 2.4 2.9 0.8 9.1 2.7 0.8 0.7

Death from heart diseases 221 167 131 191 220 297 71 172 211 300

a. Enter the data into your calculator and make a scatter plot.

b. Use your calculator’s regression function to find the equation of the least-squares regression line. Add this to your scatter plot from part a.

c. Explain in words what the slope and y-intercept of the regression line tell us.

d. How well does the regression line fit the data? Explain your response.

e. Which point has the largest residual? Explain what the residual means in context. Is this point an outlier? An influential point? Explain.

f. Do the data provide convincing evidence that there is a linear relationship between the amount of alcohol consumed and the heart disease death rate? Carry out an appropriate test at a significance level of 0.05 to help answer this question.

**82.**

Size (ounces) Cost ($) Cost per ounce

16 3.99

32 4.99

64 5.99

200 10.99

a. Using “size” as the independent variable and “cost” as the dependent variable, draw a scatter plot.

b. Does it appear from inspection that there is a relationship between the variables? Why or why not?

c. Calculate the least-squares line. Put the equation in the form of: ŷ = a + bx

d. Find the correlation coefficient. Is it significant?

e. If the laundry detergent were sold in a 40-ounce size, find the estimated cost.

f. If the laundry detergent were sold in a 90-ounce size, find the estimated cost.

g. Does it appear that a line is the best way to fit the data? Why or why not?

h. Are there any outliers in the given data?

i. Is the least-squares line valid for predicting what a 300-ounce size of the laundry detergent would you cost? Why or why not?

j. What is the slope of the least-squares (best-fit) line? Interpret the slope.