Question

(PSY 230) Statistics Use IBM SSP software to answer this problem.

According to the Center for Disease Control (2016), the mean height of adults ages 20 and older is about 66.5 inches (69.3 inches for males, 63.8 inches for females). We will test if the mean height of our sample data (n = 30) is significantly different than 66.5 inches (our test statistic) using a one-sample t-test. Conduct a two-tailed, one-sample t-test with alpha set at .05. Height of subjects (n = 30): 60.5, 70.5, 65, 66, 66, 62, 64.5, 67, 68, 65, 64, 62, 63, 63, 62.5, 65.6, 70, 72, 65, 63, 64.5, 66, 62, 61, 63, 64, 67, 65, 66, 64.5

Answer 1

From the given sample data : n=30 , ,

Therefore , The sample size is , n=30

The sample mean is ,

The sample standard deviation is ,

1) Hypothesis : Vs  

Here , teh test is two-tailed test.

2) The critical values are ,

The Excel function is , =TINV(0.05,29)

The rejection rule is , Reject Ho , if or

3) The value of the test statistic is ,

4) Decision : Here ,

Therefore , reejct Ho.

5) Conclusion : Hence , there is sufficient evidence to support the claim that the mean height of adults ages 20 and older is different from  66.5 inches.