A survey was taken of a large sample of students at a particular university. Among other things, they were asked to report how many credits they were taking, and how many hours they had slept the night before.
a. If there is indeed a relationship between number of credits taken and hours slept, should we expect it to be positive or negative? Explain.
b. Use software to access the student survey data. Regress hours slept on credits; report the correlation r and the P-value.
c. Tell whether or not there is evidence of a relationship between credits and hours slept in the larger population of students. If there is, tell whether the relationship is positive or negative.
d. Either with software or by looking at the scatterplot, explain what all the influential observations have in common.