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LabTech is a company that manufactures microscopes and other laboratory instruments . On occasion, one of the microscopes is defective when it comes off of the production line. The probability that a microscope is defective is 0.17%. Find the probability that one of the first 50 microscopes is defective .

8%
11%
23%
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.