Question

The mean score on a science assessment for 59 male high school students was 319.5 and the standard deviation 2.5. The mean test score on the same test for 40 female high school students was 298.9 and the standard deviation was 1.2. At a 002, can you support the claim that mean scores on the science assessment for male high school students were higher than for the female high school students? a. Claim: ?? Ha: LTT, RTT or TTT? b? c. Hypothesis testing to use: Why? Siandardzed test statiatic Gormula and value) . P-value Decision: Interpretation: At ?= ,

Answer 1

Null hypothesis: That is, mean scores on the science asses sment for male high school students were same as for the female high school students Alternative hvpothesis: That is, mean scores on the science assessment for male high school students were higher than for the female high school students. 2 sample z-test should be used. Because the sample size for both samples are larger than 30. Excel add-in (Mega Stat) procedure:

Step 1: In EXCEL, Select Add-Ins> Mega Stat> Hypothesis Tests. Step 2: Choose Compare Two Independent Groups. Step 3: Choose Summary Input. Step 4: In Group 1, enter B1:B4 (Select ranges with label mean, SD, n). Step 5: In Group 2, enter D1:D4 (Select ranges with label mean, SD, n). Step 6: Enter 0 Under Hypothesized difference. Step 7: Check z-test, enter Confidence level as 98.0 Step 8: Choose greater than in alternative. Step 9: Click OK. Excel add-in (Mega Stat) output:

Hypothesis Test: Independent Groups (z-test) Male Female 319.5 298.9 mean 25 12std. dev. 59 40 20.6000 difference (Male Female) 0.3767 standard error of difference 0 hypothesized difference 54.68 z 0.00E+00 pvalue (one-tailed, upper) Thus the value of test statistic is 54.68. Thus the p-value is 0 Decision rule:

If p-value α(-0.02). then reject the null hypothesis Ho- Conclusion: Use a significance level, α-0.02 Here, p-value is 0, which is lesser than the value of α-0.02. That is, p-value(-0)<α(-0.02) Therefore, by the rejection rule, reject the null hypothesis H Interpretation There is sufficient evidence at level of significance α 0.02 That is, mean scores on the science ass essment for male high school students were higher than for the female high school students.