a standardized reading test was administered to a sample of 16 sixth-grade students enrolled in a special enrichment program. in the eighth month of the school year their mean grade-equivalent score on the standardized reading test was 7.88. the variance for the 16 pupils was calculated to be 3.24. the investigator wanted to conduct a test to see if she can conclude that the pupils in the enrichment program has a mean differs from the mean of all pupils in the nation, which is 6.8. what is the null hypothesis for this test?
