Applicants for a particular job, which involves extensive travel in Spanish speaking countries, must take a proficiency test in Spanish. The sample data below were obtained in a study of the relationship between the numbers of years applicants have studied Spanish and their score on the test. Number of years (x) 3 4 4 2 5 3 4 5 3 2.
Score (y) 57 78 72 58 89 63 73 84 75 48

Required:
a. What is the correlation coefficient r2?
b. At the 5% level of significance, do the data provide sufficient evidence to conclude that the slope of the population regression line is not zero and hence that the number of years of study is useful as a predictor of score on the test?
c. Does the data provide sufficient evidence to conclude that the number of years of study and test score are linearly positively correlated?