Preview File Edit View Go Tools Window Help MO Q 8 Mon 06 Jun 06:14 Exam questions.pdf Page 5 of 5 1 Q Q b Q Search Question 8 [25 marks] Your given Ex = 44, E x2 = 174, Exy = 1324, in addition you also given the values of y as: Y 26 28 24 18 24 36 25 31 37 30 32 3a. calculate the Pearson correlation coefficient [7] 3b. estimate the y value associated with x=4 [8]. 3c. You are given the mean of 20.3 for a random sample of 90 observations from a normal distribution population with a standard deviation of 3.9. Construct a 95% confidence level and interpret your answer. [3] You are given revenue groups and the random number of days a shoe shop recorded in 300 days. revenue group 500-750 751-1001 1002-1252 1253-1503 1504-1754 1755-2005 (in Rands) number of 15 23 55 92 65 50 days(frequency) 3d. Using the Pearson's coefficient of the above distribution, comment on the skewness of the distribution [3] 3f. You are given the following information of a company that produces cola fizzy drinks. The company states that the mean caffeine content per bottle of a fizzy drink is 40 mg with a standard deviation of 7.5 mg. The quality controller is convinced that it is lower. A sample of 30 randomly drawn bottles has a mean caffeine content of 39.2 mg. Can the quality controller reject the claim? Conduct a hypothesis test at 0.05 level of significance. [4] Help 6 tv I A O