Jonathon has invested money in a savings account that earns 2.25% interest per year. the interest is compounded monthly. an expression that represents the change based on the number of years t is (1+0.0225/12)^12t. what is the percent rate of change each year? (round to the nearest hundredth)

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.