Independent t-Test Lab
Data files are available on Canvas
Effect size calculator can be found at https://lbecker.uccs.edu/
Open the data file Independent t-Test Exercise File 1
1. Complete the following:
Bernice wishes to test the hypothesis that overweight individuals tend to eat faster than
normal weight individuals. To test this hypothesis, she has two assistants sit in a
McDonald’s restaurant and identify individuals who order the Big Mac Special (Big Mac,
large fries, and large Coke) for lunch. The Big Mackers, as they are affectionately called
by the assistants, are classified as overweight or normal-weight. The assistants identify 10
overweight and 30 normal-weight Big Mackers. The assistants record the amount of time
it takes for the individuals to complete their meals. The SPSS data file contains a
grouping variable with two levels, (overweight =1, normal-weight = 2) and time in
seconds to eat the meal.
Compute an independent-samples t-test on these data. Report the t-values and the
p-values assuming equal population variances and not assuming equal population
variances below (a and b)
Using the output, identify the following: mean eating time for overweight
individuals, standard deviation for normal weight individuals, and results for the
test of homogeneity of variances (c through e)
Based on Levene’s test, which version of the t-test should we use? Enter your
answer below.
Using the effect size calculator, calculate the Cohen’s d and report it below
In the space below, write a Results section based on your analyses
What are the t-values and p-values for: a. t= –3.98, p=<0.001
a. assuming equal population variances b. t= –5.40,p=<0.001
b. not assuming equal population variances
From the output, identify the following: c. 589.00
c. Mean eating time for overweight d. 82.95
individuals e. Levene’s Test for Equality of Variances
d. Standard deviation for normal weight was not significant, F(1, 38) = 2.75, p = .106.
individuals
e. Results for the test of homogeneity of
variances
Based on the results of Levene’s test, which Based on the results of Levene’s test (F(1,
version of the t-test should we use? 38) = 2.745, p = .106), the test is not
significant (p > .05) we assume equal
variances and should use the t-test for Equal
variances assumed
Report the effect size in APA style. What is the The effect size, as measured by Cohen’s d,
Data files are available on Canvas
Effect size calculator can be found at https://lbecker.uccs.edu/
Open the data file Independent t-Test Exercise File 1
1. Complete the following:
Bernice wishes to test the hypothesis that overweight individuals tend to eat faster than
normal weight individuals. To test this hypothesis, she has two assistants sit in a
McDonald’s restaurant and identify individuals who order the Big Mac Special (Big Mac,
large fries, and large Coke) for lunch. The Big Mackers, as they are affectionately called
by the assistants, are classified as overweight or normal-weight. The assistants identify 10
overweight and 30 normal-weight Big Mackers. The assistants record the amount of time
it takes for the individuals to complete their meals. The SPSS data file contains a
grouping variable with two levels, (overweight =1, normal-weight = 2) and time in
seconds to eat the meal.
Compute an independent-samples t-test on these data. Report the t-values and the
p-values assuming equal population variances and not assuming equal population
variances below (a and b)
Using the output, identify the following: mean eating time for overweight
individuals, standard deviation for normal weight individuals, and results for the
test of homogeneity of variances (c through e)
Based on Levene’s test, which version of the t-test should we use? Enter your
answer below.
Using the effect size calculator, calculate the Cohen’s d and report it below
In the space below, write a Results section based on your analyses
What are the t-values and p-values for: a. t= –3.98, p=<0.001
a. assuming equal population variances b. t= –5.40,p=<0.001
b. not assuming equal population variances
From the output, identify the following: c. 589.00
c. Mean eating time for overweight d. 82.95
individuals e. Levene’s Test for Equality of Variances
d. Standard deviation for normal weight was not significant, F(1, 38) = 2.75, p = .106.
individuals
e. Results for the test of homogeneity of
variances
Based on the results of Levene’s test, which Based on the results of Levene’s test (F(1,
version of the t-test should we use? 38) = 2.745, p = .106), the test is not
significant (p > .05) we assume equal
variances and should use the t-test for Equal
variances assumed
Report the effect size in APA style. What is the The effect size, as measured by Cohen’s d,
