The study described in the Exercise 10.18 also evaluated personal income by gender. The average earnings per year were $35,800 for men with a standard deviation of $14,600. The average earnings for women were $23,900 with a standard deviation of $21,900. Software shows the following results:

a. Does it seem plausible that employment has a normal distribution for each gender? Explain.
b. What effect does the answer to part a have on inference comparing population means? What assumptions are made for the inferences in this table?
c. A 95% confidence interval for the difference in the population means for women and men is ($9,547, $14,253). Interpret, indicating the relevance of $0 not falling in the interval.

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Two-Sample T-Test and CI Sample N Mean StDev SE Mean 496 35800 1600656 476 23900 21900 100 Dit terence u (2) Estimate for difference: 11900 95% CI for difference: (9547, 14253) T-Test of difference vs not-: T-Value 9.93 F Velue-0.000 DE-822