I need someone to complete my statistic psychology homework (SPSS)

Kukucka/Perillo Stats 1

One-Sample t-Test Example in SPSS

The results of a recent national survey found that the average college student in the United States watches μ = 8.00 hours of television every week.

Dean Wormer of Madeup University then asked 20 Madeup students how many hours of TV they watch per week. He believes that Madeup students watch less television, on average, than typical college students do.

The datafile CollegeGPA.sav contains the data for these 20 Madeup students.

Step 1: What test should we use to test this hypothesis?

Because we want to compare the mean of our sample (which is continuous) against the mean of the entire population, we use a one-sample t-test.

Step 2: How do we run this test in SPSS?

 Go to “Analyze”  “Compare Means”  “One-Sample t-Test”

 The “Test Variable” is the variable we want to analyze (i.e., Hours of TV per week).

 The “Test Value” is the population mean (μ – in this case, 8) against which we want to compare our sample mean. Be sure to tell SPSS what this value is before you click OK!

Kukucka/Perillo Stats 2

Step 3: How do we read the output from SPSS?

One-Sample Statistics

N Mean Std. Deviation Std. Error Mean

Hours of TV per week 20 6.6500 2.73909 .61248

1: Our sample consisted of N = 20 Madeup students.

2: On average, these students watch 6.65 hours of TV per week (SD = 2.74 hours). Note that SPSS also automatically calculates the standard error for us (SE = 0.61).

3: SPSS reminds us of the hypothesized population mean that we input earlier (μ = 8).

4: These are the t (-2.20) and df (19) values for our t-test. We will need to include these in our write-up of the results, but they aren’t terribly interesting on their own.

5: This is our p-value (p = .040), which tells us if the observed difference is significant (or not). Because our p-value is less than .05, we REJECT the null hypothesis and conclude that Madeup students (M = 6.65) watch less TV than the average college student (μ = 8).

6: Calculate your d effect size. d = (6.65 - 8)/(2.73909) = -0.49

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Kukucka/Perillo Stats 3

A few things to notice about our write-up...

1) We always begin our write-up by explicitly stating our hypothesis.

2) Then, we name which test we did, and explain what the test showed. Did we, or didn’t we, find a significant difference? This is where we will provide our test statistic (in this case, our t value), degrees of freedom, and our p-value.

3) Finally, we describe our results by providing the sample size (n), mean (M), and standard deviation (SD), and providing the population mean (μ) for comparison.

4) Notice that all non-Greek letters are italicized, every equals sign has a space both before and after it, and every number is rounded to two decimal places (except for p values, which are rounded to three decimal places).

Step 4: How do we write up the results in APA format?

We hypothesized that Madeup students watch fewer hours of TV per week than

the average college student. A one-sample t-test found a significant difference between

Madeup students and the general population, t(19) = -2.20, p = .040, d = -0.49. Supporting

our hypothesis, Madeup students (n = 20) watched significantly fewer hours of TV per

week (M = 6.65, SD = 2.74) than the average U.S. college student (μ = 8.00).