b) Suppose the expected average performance in the examination was 72 percent, would we be right to say that this group of candidates performed below the average? c) A sample of 50 mores was obtained from 2011 series of a similar examination. The sample gave a mean score of 66.7 percent with a standard deviation of 3 percent. Would be right to conclude that there was no difference in performance between 2011 and 2012 scores of the examination. Question 4 In a study to analyse performance of QA in a 2015 examination series the following scores in a percentage were compiled for a sample of 100 candidates. 42,51,52,53,61,62,63,64,71,72,81,46,53,54,55,63,64,65,66,73,74,82,48,57,58,59,67,68,69,77,78, 87,43,54,56,64,65,66,67,74,75,84,47,52,53,54,62,63,64,65,72,73,82,45,56,57,58,66,67,68,69,76, 77,86,44,55,56,57,65,66,67,75,76,85,49,50,51,52,60,61,62,70,71,51,52,53,61,62,63,71,72,58,59, 57,68,69,67,78,79,80 a) Arrange the data in equal classes of size 10 starting from 40 percent. b) Using an ogive for the data, find i) The approximate percentage of the candidates who passed the examination if the pass mark was 62.5 percent. ii) The pass marks if 90 percent of the candidate passed examination. c) Verify whether it would be appropriate to use the properties of normal probability distribution in analyzing the data (perform acid test of normality). nllnann R