PSY 315 WEEK 4 PROBLEMS BY Broca1692 Week 4 Practice Problems 1 1 . List the five steps of hypothesis testing, and explain the procedure and logic of each Step 1: During this step of hypothesis testing, the query is stated again as a research theory and a null theory regarding the populations. The null and research hypothesizes are the opposites of each other. This step is necessary because it explains the theory and recognizes the populations, which will be worked throughout the study.
Step 2: During this second step, the characteristics of the comparison distribution is determined. In instances that the null theory is correct, the comparison distribution is compared to the score depending on the sample’s outcomes. Step 3: During this third step, the cutoff sample score on the comparison distribution at which the null hypothesis should be rejected is determined (Aron, Aron, and Coups, 2009). Here a researcher rejects the null hypothesis if the point of the cutoff sample score reaches or exceeds the sample score.
If the null hypothesis is true the Z score is set as a score, which is actually unlikely. Step 4: This is the step in which the test’s sample results are gathered and the sample’s score on the omparison distribution is determined. Step 5: Lastly, this is when the decision whether the null hypothesis is rejected or not is made. A researcher either declares the test invalid or rejects the null hypothesis by comparing the cut off z score to the sample’s Z score. 14. Based on the information given for each of the following studies, decide whether to reject the null hypothesis.
For each, give (a) the Z-score cutoff (or cutoffs) on the comparison distribution at which the null hypothesis should be rejected, (b) the Z score on the comparison distribution for the sample score, and (c) your conclusion. Assume that all populations are normally distributed. Population Study 5 7 Sample score p Tails of Test A . 01 . 05 1 (high predicted) B 1 (high predicted) D 2 A. )(a) 1. 64 Z score cutoff, (b) Z=2 (c) reject the null hypothesis B. )(a) 1. 96 Z score cutoff, (b) Z=2 (c) reject the null hypothesis C. )(a) 2. 3263 Z score cutoff, (b) Z=2 (c) fail to reject the null hypothesis D. )(a) 2. 76 Z score cutoff, (b) Z=2 (c) fail to reject the null hypothesis 18. A researcher predicts that listening to music while solving math problems will make a particular brain area more active. To test this, a research participant has her rain scanned while listening to music and solving math problems, and the brain area of interest has a percentage signal change of 58. From many previous studies with this same math problems procedure (but not listening to music), it is known that the signal change in this brain area is normally distributed with a mean of 35 and a standard deviation of 10. (a) Using the . 1 level, what should the researcher conclude? Solve this problem explicitly using all five steps of hypothesis testing, and Illustrate your answer wltn a sketcn snowlng tne comparlson OlstrlDutlon, tne cutoff (or cutoffs), and the score of the sample on this distribution. b) Then explain your answer to someone who has never had a course in statistics (but who is familiar with mean, standard deviation, and Z scores). a. ) First and Foremost, the researcher should conclude whether there is or is not sufficient data and statistical evidence that music actually increase math problem solving skills in people.
Below all five steps of hypothesis testing will be examined to determine what the researcher should conclude: Step 1: Since the question needs to be restated as a research hypothesis and a null hypothesis about the populations, the new question would be Does listening to music while solving math problems make a particular brain area more active? ” (Whitaker, 2013). Population 1: Music increases math problem solving skills. Population 2: Music has no effect on math problem solving skills. Step 2:This step determines the characteristics of the comparison distribution.
Therefore, in this research, it is assumed that music increases math problem solving skills. Since the null hypothesis is “music has no effect on math problem solving skills , the comparison distribution is population two’s distribution. Step 3: Since during this tep, the researcher has to “determine the cutoff sample score on the comparison distribution at which the null hypothesis should be rejected”, the null hypothesis will be rejected if the music has no effect on math problem solving skills score is within the bottom or the top 2. % of the comparison distribution (Aron, Aron, and Coup, 2009). Furthermore the cutoff Z scores for the 1% level are -2. 33 or 2. 33. Step 4: The sample’s score on the comparison distribution is determined which in his case is Z= (x-m)/s = (58-35)/10=2. 30 Step 5: This is the step in which the null hypothesis is rejected or not. Therefore, in this case since 2. 30 < 2. 3263 , the null hypothesis fails to reject. b. ) The null hypothesis failed to rejected because the p-value is greater than 1%.
Furthermore, the result of this particular and one test is not sufficient evidence and data to reject the belief that the mean percentage is 0. 35. Below there is sketch showing the comparison distribution: (Whitaker, 2013). ReTerences Aron, A. , Aron, E. N. , & Coups, E. (2009). Statistics for psychology (5th ed. ). Upper Saddle River, NJ: Pearson Prentice Hall. Whitaker, S. (2013). Individual Assingment . A Student of Psychology: A Walk Through the Human Mind .