Answer to Question #17337 in Statistics and Probability for Dion

Question

A random sample of 50 four-year olds attending day care centers provided a yearly tuition average of $3,987 and the population standard deviation of $630. Find the 90% confidence interval of the true mean.

Answer 1

x-bar = 3648
standard error = E = 1.645 * [630/sqrt(50)]= 146.56
CI: x-bar - E < mu < x-bar + E
3501.44 < mu < 3794.56