1. Statistical Inference for Managers
Presentation for Correlation By
Imran Khan

2. What is Correlation?
It is a measure of strength of relationship between two variables X & Y. It is calculated as: r= Sample correlation coefficient =

3. Properties of correlation coefficient
The correlation between X & Y is same as the correlation between Y & X
The correlation coefficient can take values between -1 & +1

4. Example
An instructor in a statistics course set a final examination and also required the students to do a data analysis project. For a random sample of 10 students, the scores obtained are shown in the table. Find the sample correlation between the examination and project scores. Examination Project

5. Spearman rank correlation
Spearman rank correlation coefficient: r=

6. Example
Students in an e-business technology course were given a written final examination as well as a project to complete as part of their final grade. For a random sample of 10 students, the scores on both the exam and the project are: Exam Project: Find the spearman rank correlation coefficient.