Question

Great white sharks are big and hungry. Here are the lengths in feet of 44 great whites.

18.9, 16.3, 13.3, 19.0,12.4 ,16.6, 15.8 ,16.1 18.4 17.6 14.2 22.6 16.4 16.3 16.8 16.8 15.5 12.5 9.4 13.4 18.1 17.7 18.4 13.2 14.8 14.0 13.3 15.8 15.8 12.3 13.8 19.6 14.8 15.1 15.1 18.9 17.6 14.6 16.3 13.2 11.9 12.2 13.4 16.7

Examine these data for shape, center, spread and outliers. The normal quantile plot indicates the distribution is reasonably Normal except for one outlier in each direction. Because these are not extreme and preserve the symmetry of the distribution, use of the t procedures is safe with 44 observations.

(a) Find the sample mean and sample standard deviation. x = ft (Round to 2 decimal places.) s = ft (Round to 3 decimal places.)

(b) The standard error of sample mean is SE(x) = ft. (Round to 3 decimal places.)

(c) Use these data to give a 95% confidence interval for the mean length of all great white sharks. to ft (Round to 2 decimal places.)

Answer 1