Statistics

Question 1

1. Describe the general characteristics of a research study for which an independent-measures t would be the appropriate test statistic.

Question 6

One sample has SS = 32 and a second sample has SS = 48.

1. Calculate the variance for each sample and the pooled variance, assuming that n = 5 for both samples. You should find that the pooled variance is halfway between the two sample variances.
2. Now assume that the first sample has n = 9 scores and the second has n = 4. Calculate the variance for each sample and the pooled variance. This time you should find that the pooled variance is closer to the value for the larger sample.

Question 11

In a study examining the permanence of academic learning, Bahrick and Hall (1991) tested knowledge of high school algebra for two groups of participants 50 years after they graduated from high school. One group had received additional college math courses and the other group had no advanced math courses in college. The following table shows data similar to Bahrick and Hall’s results. Do the data indicate a significant difference between the two groups? Use a two-tailed test with = .05.

No College Math Additional Math

n = 4 n = 8

M = 42 N = 50

SS = 100 SS = 140

Question 20

Stephen Schmidt (1994) conducted a series of experiments examining the effects of humor on memory. He collected a set of humorous sentences and then modified each one to produce a non-humorous version of the same sentence. The humorous sentences were then presented to one group of participants and the non-humorous sentences were presented to another group. Each group was then given a test to determine how many sentences they could recall. Data similar to those obtained by Schmidt are shown in the following table.

Number of sentences recalled:

Humorous Non-humorous

4 5 2 4 5 2 4 2

6 7 6 6 2 3 1 5

2 5 4 3 3 2 3 3

3 3 5 3 4 1 5 3

1. Do the data provide enough evidence to conclude that humor has a significant effect on memory? Use a two-tailed test at the .05 level of significance.
2. Calculate Cohen’s d to evaluate the size of the effect.
3. Calculate the percentage of variance explained by the treatment, r 2, to measure effect size.

SPSS Assignment

The Oak Harbor School used the Dumbarton University Math Battery (DUMB) to test the math achievement of the two 6th-grade sections. The principal’s goal was to determine if one method for teaching math was better than another. Section 1 used the standard Oak Harbor curriculum of lecture, homework, and drill. Section 2 used a problem-based learning curriculum. Using the scores recorded in the Oak Harbor 1.sav file (the same data file used in Week 7):

• State the null and alternative hypotheses for the principal’s experiment.
• Perform an independent samples t test in order to test the hypothesis and the .05 level.
• Copy or copy object and paste relevant output from the statistical test.
• State whether or not the null hypothesis is accepted or rejected based on the results of the statistical test. Decide whether you accept or reject the null hypothesis.
• In a brief paragraph (3–5 sentences), discuss what it means to accept or reject the null hypothesis in terms of the different curricula used.
• Save your data file for future use.

Price: $17.37

Solution: The downloadable solution consists of 8 pages, 937 words and 2 charts.
Deliverable: Word Document