Problem 1. A study of the annual growth of certain cacti showed that 9 of them, selected at random in a certain desert region, grew on 9, 10, 9, 9, 7, 8, 6, 10 and 13 mm. a) Find the mean and the...

Extracted text: Problem 1. A study of the annual growth of certain cacti showed that 9 of them, selected at random in a certain desert region, grew on 9, 10, 9, 9, 7, 8, 6, 10 and 13 mm. a) Find the mean and the standard deviation. b) Construct a 99% confidence interval for the average. c) Test H, : u = 10.42 mm against H, : µ<10.42 mm="" at="" the="" level="" of="" significance="" 0.05="">