Observation

The Chief Examiner reported that although this question attracted majority of the candidates, their performance was poor. According to the report, they performed better in part (a) than in part (b).
In part (a) as reported, some candidates did not adhere to the rubrics of the question. They were expected to use an assumed mean but they used the true mean and as a result, they made some computation errors due to the decimals involved. Candidates were expected to obtain the following table: