A coffee shop owner wishes to test the null hypothesis: the average amount of time customers spend in her coffee shop is 45 minutes vs. the alternative hypothesis: the average amount of time customers spend in her shop is less than 45 minutes.
A simple random sample of 64 customers is taken. On average these customers spent 42.9 minutes in the coffee shop with a standard deviation of 12 minutes.
a) Find the value of the appropriate test statistic.
b) Find the p-value.
c) According to your answer to (b), the shop owner has/does not have (circle one) significant evidence that the average amount of time customers spend in her coffee shop is less than 45 minutes.