Suppose a sample of 10 people had their foot lengths (cm) and heights (inches) measured. The results, along with the regression line, are shown in the scatterplot below. The equation of the regression line, correlation coefficient, and r² are also shown. Which one of the applet screenshots of null distributions for Exercise 10.4.2 displays the appropriate way to test whether there is a positive relationship between people€™s foot length and height?

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78 72 - 66 60 54 - 20 24 28 32 36 Footlength Height (a) (b) O Correlation o Slope O t-statistic O Correlation o Slope O t-statistic 160 Mean = 0.014 SD = 0.517 Num samples = 1000 160 Mean = 0.014 SD = 0.517 Num samples = 1000 120 120 80 80 40 40 -1.800 -0.900 0.900 1.800 -1.800 -0.900 0.900 1.800 Shuffled slopes Shuffled slopes Count Samples Greater Than 0.7 Count Samples Greater Than |1.10 Count Count Count = 88/1000 (0.0880) Count = 11/1000 (0.0110) (d) (c) O Correlation o Slope O t-statistic O Correlation o Slope O t-statistic 160 Mean = 0.014 SD = 0.517 160 | Mean = 0.014 SD = 0.517 Num samples = 1000 120 Num samples = 1000 120 80 80 40 40 -1.800 -0.900 0.900 1.800 -1.800 -0.900 0.900 1.800 Shuffled slopes Shuffled slopes Count Samples Beyond Count Samples Beyond 0.7 Count 1.10 Count Count = 189/1000 (0.1890) Count = 25/1000 (0.0250) Count Count Count Count