Paper 4: Fundamentals of Business Mathematics & Statistic

6.38 I FUNDAMENTALS OF BUSINESS MATHEMATICS AND STATISTICS

Correlation and Regression

Solution:

Given

AX= Assume mean of X series = 4

AY = Assume mean of Y series =10

N = 5

X^ =10

Y^ =20

∑dX = sum of deviations taken from assumed mean of x series = ∑(X - 4) =?

∑dY = sum of deviations taken from assumed mean of y series = ∑(Y - 10) =?

Σd^2 X^ = 100, ΣdY^2 =^160 Σd dX Y= 80

we know X A= X+^ NdX

10 4 dX

= + 5

10 4 dX

− = 5

d 6x5X=

d 30X=

Y AY dY

= + N

20 10 dY

= + 5

20 10 dY

− = 5

5 10 d× = (^) Y
dY = 50

( )

X Y X Y

XY 2

(^2) Y Y
d d d d
b N
d d
N

−

=

−

( )^2

80 30x50

5

160 50

5

−

=

−