sec83 - Math 2311 Class Notes for Section 8.3 8.3 Comparing...

This preview shows pages 1–2. Sign up to view the full content.

Math 2311 Class Notes for Section 8.3 8.3 – Comparing Two Means Two – sample t – tests compare the responses to two treatments or characteristics of two populations. There is a separate sample from each treatment or population. These tests are quite different than the matched pairs t – test discussed in section 8.1. How can we tell the difference between dependent and independent populations/samples? The null and alternate hypotheses would be: H 0 : μ 1 = μ 2 H a : μ 1 > μ 2 or H 0 : μ 1 = μ 2 H a : μ 1 < μ 2 or H 0 : μ 1 = μ 2 H a : μ 1 μ 2 And the assumptions for a two-sample t – test are: 1. We have two independent SRSs, from two distinct populations and we measure the same variable for both samples. 2. Both populations are normally distributed with unknown means and standard deviations. (Or if each given sample size is greater than or equal to 30.) Two-sample t – test statistic: t = ( x 1 x 2 ) ( μ 1 μ 2 ) s 1 2 n 1 + s 2 2 n 2 The degrees of freedom is equal to the smaller of n 1 1 and n 2 1 .

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.

{[ snackBarMessage ]}

What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern