{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

lecture7_2slides

# lecture7_2slides - Statistics 528 Lecture 7 Section 2.2...

This preview shows pages 1–3. Sign up to view the full content.

Statistics 528 - Lecture 7 1 Statistics 528 - Lecture 7 Prof. Kate Calder 1 Section 2.2 - Correlation Statistics 528 - Lecture 7 Prof. Kate Calder 2 Sometimes it is difficult to judge the strength of a relationship by eye => need a numerical measure of strength to supplement a scatterplot CORRELATION (r) - measures the strength and direction of the linear relationship between two quantitative variables. where and are the means of the x -values and y -values, respectively, and s x and s y are the corresponding standard deviations. ° = ± ± ± ² ³ ´ ´ ´ µ - ± ± ² ³ ´ ´ µ - ± ² ³ ´ µ - = n i y s y i y x s x i x n r 1 1 1 x y

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Statistics 528 - Lecture 7 2 Statistics 528 - Lecture 7 Prof. Kate Calder 3 Correlation is an “average” of the product of the standardized values of the two variables. The sign of r gives the direction of the relationship. r > 0 => positive association r < 0 => negative association Strength is on a scale 0 to 1.
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