In: Statistics and Probability
Managers rate employees according to job performance and attitude. The results for several randomly selected employees are given below. Performance (x) / 3 / 2 / 3 / 7 / 4 / 8 / 2 / 2 / 2 / 6 Attitude (y) / 2 / 2 / 1 / 7 / 7 / 6 / 2 / 8 / 5 / 4 Use the given data to find the test statistic for testing linear correlation. Round the final values to three significant digits, if necessary.
First we need to calculate the correlation between Performance(x) and attitude(y)
We shall be using the formulae below:
where
we shall form the squares and cross product tables below:
x | y | ||||
3 | 2 | 9 | 4 | 6 | |
2 | 2 | 4 | 4 | 4 | |
3 | 1 | 9 | 1 | 3 | |
7 | 7 | 49 | 49 | 49 | |
4 | 7 | 16 | 49 | 28 | |
8 | 6 | 64 | 36 | 48 | |
2 | 2 | 4 | 4 | 4 | |
2 | 8 | 4 | 64 | 16 | |
2 | 5 | 4 | 25 | 10 | |
6 | 4 | 36 | 16 | 24 | |
Total | 39 | 44 | 199 | 252 | 192 |
Testing correlation coefficient:
Test statistic
. The critical value of t at n-1=10-2=8 df is 2.306. Since the calculated value of t <teh critical value,we do not reject the null hypothesis. Hence we conclude that there is not enough evidence that there is linear relationship between performamnce and attitude.