1. A researcher claims that a patient takes on the average 11.8 months to fully recover from a knee surgery. A random sample of 60 patients were studied and the results showed a mean of 10.2 months and a standard deviation of 3.2 months. (a) Find a 95% confidence interval for estimating the average recovery period. (6) (b) Is there enough evidence to support the claim on average recovery time? Test at 0.01 level of significance and provide your conclusion. [All work must be shown] ( 14 )