Paper 4: Fundamentals of Business Mathematics & Statistic

FUNDAMENTALS OF BUSINESS MATHEMATICS AND STATISTICS I 6.27

Y Y b (x x)− = YX −

( )

YX X Y X Y

2

(^2) X X
d d - d d
Where b =
d d
N

YX ( ) 2

b 135 ( 4)( 24)

50 4

5

= − − −

− −

135 96

50 16

5

= −

−

(^3939) 0.83
=50 3.2 46.8− = =
Y Y b (X X)− = YX −
Y – 20.2 = 0.83 (X – 14.2)
Y – 20.2 = 0.83 X – 0.83 X 14.2
Y = 0.83X – 11.78 + 20.2
Y = 0.83X + 8.42
6.2.8. REGRESSION COEFFICIENTS
The regression coefficient gives the value by which one variable increases for a unit increase in other variable,
bXY and bYX are two coefficient of regression.
Regression coefficient of x on y or bxy can be calculated by any of the following ways—
(1) when standard deviation are given
XY
b r X
Y
= σ
σ
(2) when deviations are taken from actual mean
XY 2
b XY
= Y
(3) when deviations are taken from assumed mean

( )

XY X Y X 2 Y

(^2) Y Y
b d d d d
d
d N
=^ −