The average score on a nationwide standardized test is found to be 124 with a standard deviation of σ = 8.4. We at GCA believe our students scored better than average on the test. A sample of 40 GCA student's scores was taken. The average score for the sample was 126, A hypothesis test is conducted at the .05 significance level.

Which of the following is the correct test statistic for the hypothesis test?

z = -1.51

z = 1.51

z = 2.65

z = -2.65

Question

The average score on a nationwide standardized test is found to be 124 with a standard deviation of σ = 8.4.  We at GCA believe our students scored better than average on the test.  A sample of 40 GCA student's scores was taken.  The average score for the sample was 126,  A hypothesis test is conducted at the .05 significance level.

Which of the following is the correct test statistic for the hypothesis test?
	
z = -1.51

	
z = 1.51

	
z = 2.65

	
z = -2.65

directrix · Answer

z = (x-bar - µ)/(σ/sqrt(n))

z = (126 - 124)/(8.4/sqrt(40)) 

z = 1.51