CEO pay. A study of 104 corporations found that the pay of their chief executive officers had increased an average of x = 6.9% per year in real terms.

The standard deviation of the percentage increases was s = 17.4%.

(a) The 104 individual percentage increases have a right-skewed distribution.

Explain why the central limit theorem says we can nonetheless act as if the mean increase has a Normal distribution.

(b) Give a 95% confidence interval for the mean percentage increase in pay for all corporate CEOs.

(c) What must we know about the 104 corporations studied to justify the inference you did in (b)?