In a service company, we obtained using an appropriate evaluation test, the level of satisfaction with their work and the number of days of absence during the last year, and this for a random sample of 13 employees.

Satisfaction level (x)	Number of days of absence (y)	Satisfaction level (x)	Number of days of absence (y)
50	16	54	8
76	5	33	15
77	13	90	3
62	6	56	10
47	18	82	6
70	7	39	16
45	14

We want to use linear regression as a statistical tool to predict the number of days absence according to the level of job satisfaction. Some preliminary calculations lead to the following results: