STP231 HW.

STP231 HW. Twenty different statistics students are randomly selected. For each of them, their body temperature (degreesC) is measured and their head circumference (cm) is measured. a. For this sample of paired data, what does r represent, and what does rho represent? b. Without doing any research or calculations, estimate the value of r. c. Does r change if body temperatures are converted to Fahrenheit degrees? - ANSWER r is a statistic that represents the value of the linear correlation coefficient computed from the paired sample data, and rho is a parameter that represents the value of the linear correlation coefficient that would be computed by using all of the paired data in the population of all statistics students. The value of r is estimated to be 0, because it is likely that there is no correlation between body temperature and head circumference. The value of r does not change, because r is not affected by converting all values of a variable to a different scale. wenty different statistics students are randomly selected. For each of them, their body temperature (degreesC) is measured and their head circumference (cm) is measured. If it is found that requals0, does that indicate that there is no association betwen these two variables? - ANSWER No, because while there is no linear correlation, there may be a relationship that is not linear. If we find that there is a linear correlation between the concentration of carbon dioxide in our atmosphere and the global temperature, does that indicate that changes in the concentration of carbon dioxide cause changes in the global temperature? - ANSWER The presence of a linear correlation between two variables does not imply that one of the variables is the cause of the other variable. Match these values of r with the accompanying scatterplots: 0.995, negative 0.995, negative 1, negative 0.376, and 0.376. - ANSWER Scatterplot 1, -0.376 Scatterplot 2, -1 Scatterplot 3, 0.376 Scatterplot 4, 0.995 Scatterplot 5, - 0.995 Use the given data set to complete parts (a) through (c) below. (Use alphaequals0.05.) x y 10 9.14 8 8.15 13 8.75 9 8.77