Chapter 25final.pdf

8 Pages
69 Views
Unlock Document

Department
Biology (Biological Sciences)
Course
BIOL499A
Professor
Blaine Mullins
Semester
Winter

Description
Chapter 25: Comparing Two Population Means – Paired Samples In this chapter, we will talk about:  The difference between independent and dependent samples,  Hypothesis tests for a matched pairs design,  Confidence intervals for   or a matched pairs design, 1 2 The blood pressure of five patients were recorded before and 30 minutes after receiving a drug. The results are given in the following table. Is the drug useful in reducing the blood pressure? Patients 1 2 3 4 5 Mean S.D. Before 146134110 126 157 134.6 18.105 After 140138110 116 144 129.6 13.822 Difference 6 -4 0 10 13 5.0 7.000 Inference about  1  2for a Matched Pairs Design: Let dyy 1 2 and d = Average of d-values s = Standard deviation of d-values. d So, we have  d 1 2 . An estimator of d is d and    ()  ()E d sd d n n To test the hypothesisH :    0 , the test statistic is: 0 1 2 d 0 TS  ~ t distribution, withdf  n 1,if H 0is true dn/ For H :0   , we rejectH ifTS  t* a d 1 2 0 * For H a d  1 2 , we rejectH 0if TS  t * * For H a d  1 2 , we reject H0if TS  t or TS  t A 100(1)% confidence interval ford 1 2 is given by: s dt * d n Example 25.1: Two computers often are compared by running a collection of different ``benchmark'' programs and recording the difference in CPU time required to complete the same program. Six benchmark programs, run on two computers, produced the following CPU times (in minutes): Benchmark Program 1 2 3 4 5 6 Computer 1 1.12 1.73 1.04 1.86 1.47 2.10 Computer 2 1.15 1.72 1.10 1.87 1.46 2.15 (a) Find a 99% confidence inte rval for the difference in mean CPU time required for the two computers to complete a job. Solution: (b) Does the data provide sufficient evidence to indicate that thmean CPU time required to complete a job is greater for computer 2 than for computer 1? Solution: Ex
More Less

Related notes for BIOL499A

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit