Question

Test the claim that the mean GPA of night students is larger than the mean GPA of day students at the 0.10 significance level. The null and alternative hypothesis would be: H 0 : p N ≥ p D H 1 : p N < p D H 0 : p N ≤ p D H 1 : p N > p D H 0 : p N = p D H 1 : p N ≠ p D H 0 : μ N ≤ μ D H 1 : μ N > μ D H 0 : μ N ≥ μ D H 1 : μ N < μ D H 0 : μ N = μ D H 1 : μ N ≠ μ D The test is: two-tailed right-tailed left-tailed The sample consisted of 30 night students, with a sample mean GPA of 3.34 and a standard deviation of 0.02, and 30 day students, with a sample mean GPA of 3.32 and a standard deviation of 0.08. The test statistic is: (to 2 decimals) Use the conservative degree of freedoms. The p-value is: (to 2 decimals) Based on this we: Reject the null hypothesis Fail to reject the null hypothesis

Answer 1

H0 : μN ≤ μD

H1 : μN > μD

Right tailed

Test statistic = 1.33

Pvalue = 0.097

Fail to reject the Null

Explanation:

H0 : μN ≤ μD

H1 : μN > μD

The test is right tailed ; culled from the direction of the greater than sign ">"

Night students :

n1 =30 x1= 3.34 s1 = 0.02

Day students:

n2 = 30 x2 = 3.32 s2 = 0.08

The test statistic :

(x1 - x2) / √(s1²/n1) + (s2²/n2)

T= (3.34 - 3.32) / √(0.02²/30) + (0.08²/30)

T = 0.02 / 0.0150554

Test statistic = 1.328

Using the conservative approach ;

df = Smaller of n1 - 1 or n2 - 1

df = 30 - 1 = 29

Pvalue(1.328, 29) = 0.097

At α = 0.10

Pvalue < α ; Hence, we reject H0 ; and conclude that there is significant evidence that GPA of night student is greater than GPA of day student