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Test the claim that the mean GPA of night students is larger than 2.2 at the .10 significance level.

User Djizeus
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This question is incomplete, the complete question is;

Test the claim that the mean GPA of night students is larger than 2.2 at the .10 significance level.

The test is based on a sample of 55 people, the sample mean GPA was 2.23 with a standard deviation of 0.06

Answer:

P-value is less than the significance level.

We reject null hypothesis.

Therefore, there is enough evidence to conclude that the mean GPA of night students is larger than 2.2

Explanation:

Given the data in the question;

Claim : The mean GPA of night student is larger than 2.2

μ = 2.2

sample size n = 55

sample mean x' = 2.23

standard deviation s = 0.06

Hypothesis

Null hypothesis H₀ : μ ≤ 2.2

Alternative hypothesis H₁ : μ > 2.2

Right-tailed Test.

Significance Level ∝ = 0.10

so critical value
t_{(0.10, df=54) = 1.297

Test Statistic

T
_{cal = (x'-μ) / (s/√n)

we substitute

T
_{cal = (2.23 - 2.2 ) / (0.06 / √55)

= 0.03 / 0.00809

T
_{cal = 3.71

T
_{cal is greater than critical value, so it falls in the rejection region;

p-value = P( t > 3.71 ) = 0.000245

P-value is less than the significance level.

We reject null hypothesis.

Therefore, there is enough evidence to conclude that the mean GPA of night students is larger than 2.2

User Lammert
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