Question

52+2.26x

(a) y=3.52

(b) y=2.26x

(c) y=4+3x

I had been asked this question in an internship interview.

Origin of the question is Curve Fitting topic in chapter Matrices of Engineering Mathematics

Answer 1

Right choice is (a) y=3.52

To elaborate: Here, N=6

Calculations of ∑x and ∑x^2

x

y

x^2

xy

0

3

0

0

1

6

1

6

2

8

4

16

3

11

9

33

4

13

16

52

5

14

25

70

∑x=15

∑y=55

∑x^2=55

∑xy=177

We know that,

∑y=Na+b∑x

∑xy=a∑x+b∑x^2

Substituting the values from the table into the equations-

55=(6)a+b(15) – (1)

177=(a)15+b(55) – (2)

Solving equations (1) and (2) simultaneously

a=3.52 and b=2.26

Thus the equation of the line is given by y=a+bx

Thus, the equation of the line is y=3.52+2.26x.