Question

Problem #2: Does presentation methodology improve retention for remembered material? You know that the average number of concepts remembered from a lecture is 20. You present information using a song to a group of four participants. Here are their scores for the number of concepts they remember from a lecture: 20, 21, 18, 29 Please conduct all steps of hypothesis testing and evaluate using a one tailed test and alpha =.01. You must use all five steps in hypothesis testing:

Restate the question as a research hypothesis and a null hypothesis about the populations.

Determine the characteristics of the comparison distribution.

Determine the cutoff sample score on the comparison distribution at which the null hypothesis should be rejected.

Determine your sample’s score on the comparison distribution.

Decide whether to reject the null hypothesis.

Answer 1

Concept

We do hypothesis testing for validating our claim. Whatever we feel/claim is considered as an alternate hypothesis and the opposite as the null hypothesis. We reject the null hypothesis if the p-value is less than alpha (significance level)

Step 1: Hypothesis statements

• Ho: The average number of concepts remembered from a lecture is 20
• Ha: The average number of concepts remembered from a lecture is more than 20

Step 2: Calculating characteristics of the sample

Sample values: 20,  21, 18, 29

• n =4
• Mean = (20+21+18+29)/4 = 22

Since we are calculating for a sample and not population, the denominator of the variance would be n-1

  

Step 3: Calculating cut off score for alpha =0.01

Since it is a one-tailed test we would reject the null if the Z score of our distribution (test statistic) is greater than the cut-off z-score, otherwise, we wouldn’t.

'Cut off score at alpha =0.01 is 2.33 (From the z-table)

Step 4: Calculating Z score of the distribution

So, Z-score of the distribution is 0.83

Step 5: Conclusion

Since Z score < cut-off score ( as 0.83< 2.33), we accept the null.

So, there is no statistically significant evidence that the average number of concepts remembered is greater than 20