Practice Problems with Dependent Sample ttest
For each of the following problems carry out the following steps:
1.
State the null hypothesis
2.
State the alternative hypothesis
3.
State what statistical test should be done and why.
4.
Carry out the appropriate test (if possible).
5.
State any possible conclusions.
The answers are linked to each problem, but you will not benefit from working the
problems ifs you examine the answer before working the problem.
Problem 1:
An experiment was performed on the effects of study skill training. A randomly
selected group of freshmen was used. The group was selected near the end of a
fall semester and their fall GPAs obtained. They took the training after exam
week in the fall. Their grades were obtained again at the end of spring semester.
The results are:
Pretraining 2.5
1.2
3.1
2.6
2.8
3.5
2.0
1.1
3.8
4.0
Posttraining 2.8
2.4
3.5
3.1
2.7
3.6
2.4
2.1
3.9
3.9
Answer 1
Problem 2:
A researcher performed an experiment to determine if the presence of pictures
facilitated or interfered with young children's learning of words. Two groups of
5 year olds were selected so that they were matched on preschool readiness. One
group received vocabulary training with the pictures the other without the
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Fall '11
 Gilbert
 Math, Null hypothesis, Statistical hypothesis testing

Click to edit the document details