You are given the following data for variables x and y:
x y
3.0…………………1.5
2.0…………………0.5
2.5…………………1.0
3.0…………………1.8
2.5…………………1.2
4.0…………………2.2
1.5…………………0.4
1.0…………………0.3
2.0…………………1.3
2.5…………………1.0
a. Plot these variables in scatter plot format. Based on this plot, what type of relationship appears to exist between the two variables?
b. Compute the correlation coefficient for these sample data. Indicate what the correlation coefficient measures.
c. Test to determine whether the population correlation coefficient is positive. Use the α = 0.01 level to conduct the test. Be sure to state the null and alternative hypotheses and show the test and decision rule clearly.