We want to conduct a hypothesis test of the claim that the population mean daily profit of a convenience store is more than 480 dollars. So, we record the daily profit for a random sample of days. The sample has a mean of 489 dollars and a standard deviation of 80 dollars. For each of the following sampling scenarios, choose an appropriate test statistic for our hypothesis test on the population mean. Then calculate that statistic. Round your answer to 2 decimal places.

a). Tha sample has size 18, and it is from a normally distributed population with an unknown standard deviation.

z=

t=

It is unclear which test statistic to use