We want to conduct a hypothesis test of the claim that the population mean reading speed of second graders is different from 31.3 words per minute, So, we choose a random sample of students' reading speeds, The sample has a mean of 30,7 words per minute and a standard deviation of 3.2 words per minute. 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 answers to two decimal places. (@) The sample has size 17, and it is from a normally distributed population with an unknown standard deviation, It is unclear which test statistic to use, X (D) The sample has size 12, and it is from a normally distributed population with a known standard deviation of 2.9. Of = 1 It is unclear which test statistic to use