EXAMPLEofH-LLeastsquares.docx

EXAMPLE

Least – Squares Regression

Formula of Least –squares

b1= [n(∑ XY) – (∑ X) (∑ Y) ]/ n(∑ X^2) – (∑ X)^2

bo = [(∑ Y) – b (∑ X)] / n

X = level of activity [ independent]

Y = Total fixed cost [dependent]

b1 = variable cost

b 0 = Fixed cost

n = number of observations

∑ = sum of all observations

Illustration

Month

X

Y

Jan

5600

7900

Feb

7100

8500

Mar

5000

7400

April

6500

8200

May

7300

9100

June

8000

9800

July

6200

7800

Total (∑ )

43,700

58,700

Month

X

Y

XY

X^2

Jan

5600

7900

44,240,000

31,360,000

Feb

7100

8500

60,350,000

50,410,000

Mar

5000

7400

37,000,000

25,000,000

April

6500

8200

53,300,000

42,250,000

May

7300

9100

66,430,000

53,290,000

June

8000

9800

78,400,000

64,000,000

July

6200

7800

48,360,000

38,440,000

Total (∑ )

45,700

58,700

388,080,000

304,750,000

b1= [n(∑ XY) – (∑ X) (∑ Y) ]/ n(∑ X^2) – (∑ X)^2

b1= [7 (388,080,000) – (45700) ( 58700)]/ 7(304,750,000) – (45,700)^2

b1 = $ 0.759

bo = (58700) – 0.759 (45,700) / 7

= $3,431

Y = 3431 + 0.759 (X)