Question 12 2 pts (CO 5) In a hypothesis test, the claim is =15.7. A sample 31 has a mean of 15 and a population standard deviation of 1.3 from a normally distributed data set. In this hypothesis test, would a z test statistic be used or a t test statistic and why? O t test statistic would be used as the data are normally distributed with an unknown population standard deviation O t test statistic would be used as the data set is small and the population standard deviation is known O z test statistic would be used as the population standard deviation is known O z test statistic would be used as the population standard deviation is unknown