7) All the students at a school took the SAT test. The average score on the test was an 75. A sample of all the students who were juniors and seniors of size 400 also took the test. It is found that...

question 7

Extracted text: 7) All the students at a school took the SAT test. The average score on the test was an 75. A sample of all the students who were juniors and seniors of size 400 also took the test. It is found that their average was a 77. It is also found that the sample standard deviation s = 3 Compute with 1% confidence whether the juniors and seniors scored on average greater that the whole body of students of not.