19

20

21

22

23

24

25

26

27

28

Total

Mean

standard deviation

variable coefficient

sale + 2

62.86

13.45

−3.32

58.64

22.59

3.04

23.62

8.30

1.65

−3.57

187.25

18.73

24.12

1.29

sale + 1

58.46

13.28

−2.72

58.05

22.57

3.64

24.60

9.30

2.65

−2.57

187.25

18.73

22.83

1.22

Begin

55.26

11.55

−1.72

57.02

22.52

4.64

25.60

10.30

3.65

−1.57

187.25

18.73

21.71

1.16