Question

Managers rate employees according to job performance and attitude. The results for several randomly selected employees are given below.

  

performance	59	63	65	69	58	77	76	69	70	64
attitude	72	67	78	82	75	87	92	83	87	78

b. Does the scatter plot show positive / negative / no correlation? Justify your answer.a. Construct a scatter plot for the given data.

c. Find the least-square regression line (Best fit line). Graph the equation on the same graph as part (b).

d. If an employee with the rating of 67 on his job performance, what is his predicted rating on the attitude?

e. Is there a linear correlation between the two variables? (Hint: apply the 4-step process of hypothesis testing)

Answer 1

b)

There seems to be a positive correlation.

c)

We will be applying the Linear regression model here, it can be done by using the function =LINEST(y_value, x_value, TRUE, TRUE) where y_values contain values of Attitude here and x_values have Performance values.

Select 5 rows and 2 columns and then write the formula in the first cell and after that, press Shift + Ctrl + Enter.    

The equation comes out to be -
Attitude = 11.7 + 1.02*performance

d)

When performance = 67

Attitude = 11.7 + 1.02*67 = 11.7 + 68.34 = 80.04    

e)

The linear correlation coefficient comes out to be 0.86.