DO NOT SOLVE! I need help understanding what planks I am supposed to be looking at. Can someone
give me a visual of which wooden slats I am suppose to visualize?

Aphrase is shown read the phrase and give me the answer

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.

Simplify each expression for 18, 20, and 21