Question

. A group of 25 students took examinations in both pure mathematics and statistics. Their marks out of 150 in mathematics, x, and in statistics, y, were recorded and are summarized below.
Σ x = 1978, Σ x2 = 175840 Σ y = 2123 Σ y2 = 202257 Σ xy = 181572
i. Calculate Sxx, Syy and Sxy
ii. Find the product moment correlation coefficient between the marks in pure Mathematics and Statistics
iii. Starting your hypotheses clearly tests, at the 5% level of significance, whether or not there is evidence of a correlation.
iv. State an assumption needed for the test in part (iii) to be valid.