Fred invests $17,954 into an account that yields 5.15% interest annually. How much interest will Fred have earned after 16 years? Round answers to the nearest cent (2 decimal places). pls urgent life kinda depends on it

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.