The test scores dropped in 2009 Design and run a hypothesis

The test scores dropped in 2009. Design and run a hypothesis test to determine if the decline represented a statistically significant decrease in the mean test score. Be sure to explain how you plan set up the test. You will need to decide what you will use as your population. Be sure to explain the result and implications of the hypothesis test.

I need to know the formula and information required to complete this problem

Solution

step 1. We should use the test scores of all the students in 2009 as population.(say, there were n students)
  2. we need to know the mean test score(say,a) and s.d of the test score(say,b) before 2009...
3. we need to know the mean score of the test for any sample of students in 2009.....(say, this is c)..
3. Test H0 : Mean test score in 2009= a ag. H1 : mean test score in 2009 < a...
  4. Test statistic = c-a / ( b / sqrt(n) ).. = e (say)..
  5. set a desired level of significance..say 0.05..
  6. find critical value. ( in this case, critical value =  1.644854...
  7. Decision : If e <  1.644854 , then we should accept H0 and if e >=  1.644854 ..we should accept H1 and reject H0 at 95% confidence..