Members of the school committee for a large city claim that the population mean class size of a middle school class within the district is exactly 20 students. Karla, the superintendent of schools for...

Members of the school committee for a large city claim that the population mean class size of a middle school class within the district is exactly 20 students. Karla, the superintendent of schools for the city, thinks the population mean is less. She selects a random sample of 35 middle school classes across the city. The sample mean is 18.5 students with a sample standard deviation of 3.7 students. The test statistic t for a hypothesis test of H0:μ=20 versus Ha:μ<20 is t≈−2.40.>

Select all that apply:

A) Reject the null hypothesis that the true population mean class size of a middle school class within the district is equal to 20 students.

B) Fail to reject the null hypothesis that the true population mean class size of a middle school class within the district is equal to 20 students.

C) There is not enough evidence at the α=0.05 level of significance to suggest that the true population mean class size of a middle school class within the district is less than 20 students.

D) There is enough evidence at the α=0.05 level of significance to support the claim that the true population mean class size of a middle school class within the district is less than 20 students.