The Castillo de San Marcos is a Spanish fortress that was built between 1672
and 1695.
a. Rounded to the nearest ten
thousand, how many pesos did it
cost to build the fortress?
It cost 138,375
pesos to build this
fortress
b. How many years did it take to build
the fortress?

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.