A construction worker uses a tape measure to find that a pipe is 28/100
of a meter long. Select the decimal that represents the same length.
a 1.28 m

b 2.8 m

c 0.28 m

d 0.028 m

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.