Jessica investigates the relationship between caffeine intake and performance on a class test for high school students. before her sample of students takes an exam, she notes the number of cups of coffee they consumed two hours before the test. she obtains their scores after the test is over. she then calculates the correlation coefficient between the two variables and finds it to be +0.82. which of the following conclusions should jessica draw from this value?
a. caffeine consumption has no association with performance on a testb. eighty-two percent of the students consumed caffeine prior to the examc. higher caffeine consumption is related to higher exam scoresd. caffeine consumption causes higher scores.