A same of 4 workers was drawn at random from two different industries, with their average annual income (in SOO) recorded, as.

(a) Using first a t-test (as in Chapter 8) and then an ANOVA F-test, calculate whether or not there is a statistically significant difference in income at the 5% level.

(b) Are: the t and F tests exactly equivalent? Can you see why the t2 distribution is often referred to as the F distribution with 1 degree of freedom in the numerator? *

(c) Using first the t distribution (8-17), and then the F distribution (10-20); construct a 95 % confidence interval for the difference in mean incomes in the two industries. >-