sattistics
posted by Jerry
Twenty students randomly assigned to an experimental group receive an instructional program: 30 in a control group do not. After 6 months, both groups are tested on their knowledge.
The experimental group has a mean of 38 on the test(with an estimated population standard deviation of 3): the control group has a mean of 35 ( with an estimated population standard deviation of 5) Using the .05 level, what should the experimenter conclude?
(a)Use the steps of hypothesis testing,
(b) sketch the distributions involved
(c) explain your answer to someone who is familiar with the t test for a single sample, but not with the t test for independent means.

Mrs. Nation
(a) and (c)
Ho: u(ex)  u(ct) = 0
Ha:u(ex) – u(ct) is not equal to 0
Test stat: t = (3835) / sqrt[9/20 + 25/30] = 2.6482
pvalue = 2*P(t > 2.6482 with df = 48) = 0.0109
Conclusion:
At the 5% significance level, reject Ho because the pvalue is less than 5%
I need part b any suggestions?
Respond to this Question
Similar Questions

Statistic
Twenty students assigned to an experimental group receive 30 in a control group has a mean of 38 on the test (with an estimated population standard deviation of 3); the control group has a mean of 35 (with an estimated population standard … 
Statistic
Twenty students assigned to an experimental group receive 30 in a control group has a mean of 38 on the test (with an estimated population standard deviation of 3); the control group has a mean of 35 (with an estimated population standard … 
Statistic
18. Twenty students randomly assigned to an experimental group receive an instructional program; 30 in a control group do not. After 6 months, both groups are tested on their knowledge. The experimental group has a mean of 38 on the … 
Psychology
Twenty students randomly assigned to an experimental group receive an instructional program; 30 in a control group do not. After 6 months, both groups are tested on their knowledge. The experimental group has a mean of 38 on the test … 
psychology
In an experiment, a control group is different from an experimental group in that the people in the control group: are not exposed to the same treatment of the independent variable. differ in trait variables. do not incur the same … 
statistics
suppost we wanted to test the hypothesis that control a group of cancer patients(group 1) would report higher mean pain ratings than an experimental group recieving special message treatment(group 2). Use the following information, … 
statistics
Twenty (20) students randomly assigned to an experimental group are studying for a test while listening to classical music. Thirty (30) students randomly assigned to a Control group are studying for the same test in complete silence. … 
Statistics
Twenty (20) students randomly assigned to an experimental group are studying for a test while listening to classical music. Thirty (30) students randomly assigned to a control group are studying for the same test in complete silence. … 
Psychology
Twenty students randomly assigned to an experimental group receive an instructional program; 30 in a control group do not. After 6 months, both groups are tested on their knowledge. The experimental group has a mean of 38 on the test … 
English
I am psueo conducting an experiment on 144 freshmen high school students who are evenly divided into 6 groups. The treatment group are receiving a new instructional strategy that the control group is not receiving. A ttest was conducted …