Solve the below:
Q: Find a confidence interval for mean assuming that each sample is from a normal population.
a. ¯x = 24, s = 3, n = 7, 90 percent confidence
b. ¯x = 42, s = 6, n = 18, 99 percent confidence
c. ¯x = 119, s = 14, n = 28, 95 percent confidence