A research firm conducted a survey to determine the mean amount people spend at

a popular coffee shop during a week. They found the amounts spent per week
followed a normal distribution, with a population standard deviation of $4. A sample
of 49 customers revealed that the mean is $25.
a) What is the 95% confidence interval estimate of µ?
b) What is the 99% confidence interval estimate of µ?

1 answer

23.88, 26.12