In: Statistics and Probability
We wish to compare the PsyCap scores of our class to a predetermined standard set by a study conducted in 2014. The population mean for this standard is 121. 58 with a standard deviation of 11.29.
Utilizing the steps of hypothesis testing, determine if the scores of our class are equal to those of the standard using a 95% confidence level.
28 | 33 | 32 | 31 | 124 | |
30 | 22 | 33 | 22 | 107 | |
32 | 29 | 31 | 27 | 119 | |
20 | 24 | 29 | 30 | 103 | |
24 | 23 | 27 | 32 | 106 | |
32 | 33 | 33 | 29 | 127 | |
29 | 22 | 27 | 24 | 102 | |
36 | 30 | 32 | 29 | 127 | |
23 | 17 | 21 | 21 | 82 | |
36 | 22 | 36 | 24 | 118 | |
24 | 29 | 26 | 25 | 104 | |
21 | 26 | 29 | 19 | 95 | |
26 | 21 | 24 | 24 | 95 | |
27 | 28 | 31 | 27 | 113 | |
Answer
Step 1
Our Hypothesis
Ho: Ho = μ = 121.58 (equal to(null))
Ha: μ ≠ 121.58 (not equal to (alternative))
Step 2
Specify the significance level a(alpha)
a = 0.05
Step 3 (also step 5)
Select the test statistic (two tailed test, this means two rejecting regions)
(103.76-121.58)/ 11.29/ square root of 17 = -6.507
0.95
0.025 0.025
-1.96 1.96
Step 4
The rule is to decide whether the z equals that of Ho, if it is less or more we reject and favor the alternative Ha
Step 5
(103.76-121.58)/ 11.29/ square root of 17 = -6.507
0.95
0.025 0.025
-1.96 1.96
Step 6 Decide whether to reject Ho
Because the result was -6.507, we choose to reject Ho
Step 7
We conclude that scores are below 2014’s data, meaning it is not equal.