QUESTION 3 (20 marks) A research officer at the Central Bank was assigned the task of determining whether the percentage changes in mortgages over a three year period for the four largest commercial banks were significantly different. The data below exhibits the percentage changes (in millions) in mortgages: Years City Bank Chance Bank United Bank Bank of Caspri 2012/13 2.5 6.0 1.2 5.8 2013/14 1.3 5.2 0.9 4.4 2014/15 0.9 3.9 0.4 4.5 TURN OVER a) At the 0.05 significance level, use the randomized block design to determine if there is evidence of a difference in the mean percentage changes of mortgages between banks? (8 marks) b) Do you think that there is a significant block effect in this investigation? Explain.