Which one of the following compound inequalities has no solution? 7x – 8 > 9(x - 1) and 3x + 2 < 5x + 3
– 2x + 5 > – 3x – 2 and – 3x – 2 > -2x + 4
- 2x + 5 < – 3x – 3 and - 4x +9 > – 5x + 2
3(x - 1) > 4(x - 2) and 2(x + 2) < 5(x - 1)

Arandom sample of n = 25 observations is taken from a n(µ, σ ) population. a 95% confidence interval for µ was calculated to be (42.16, 57.84). the researcher feels that this interval is too wide. you want to reduce the interval to a width at most 12 units. a) for a confidence level of 95%, calculate the smallest sample size needed. b) for a sample size fixed at n = 25, calculate the largest confidence level 100(1 − α)% needed.