An article in Daily Sundial reported that the average cell phone bill of college students is more than $155 per month.We believe this figure is an overstatement (exaggeration).We took a random sample of 25 students and found the average of their last month bill was $148.Assume monthly bills are normally distributed with a standard deviation of $23.

Do an hypothesis test using the p-value method with 90% confidence level.Show the null and alternative hypothesis and make a conclusion and interpret it.