EASY
12th ICSE
IMPORTANT
Earn 100

Show that if five students get respectively 1,2,3,4,5 marks (X) out of 10 in subject A, and 3,3,5,7,6 marks (Y) out of 10 in subject B, the regression equation of Y on X can be written as y=1.8+x.

Important Questions on Linear Regression

EASY
12th ICSE
IMPORTANT

Fit a straight line to the following data, treating y as the dependent variable : 

x 14 12 13 14 12
y 22 23 22 24 24

Hence, predict the value of y when x=16.

EASY
12th ICSE
IMPORTANT

Treating x as independent variable, find the line of best fit for the following data: 

x 15 12 11 14 13
y 25 28 24 22 30

Hence, predict the value of y when x=10.

EASY
12th ICSE
IMPORTANT

Find the equations of the lines of regression on the basis of following data :

x 1 2 3 4 5
y 166 184 142 180 338
EASY
12th ICSE
IMPORTANT

A manufacturer of optical lenses has the following data on the cost per unit (in Rs.) of a certain quality of lens and the number of units made in each order:

Order Number Number of units (x) Cost per unit (y)

1

2

3

4

5

6

1

3

5

7

10

15

58

52

46

40

37

22

Find the correlation coefficient. Also determine the two regression equations. 

HARD
12th ICSE
IMPORTANT

The following observations are given :

1,4, 2,8, 3,2, 4,12, 5,10, 6,14, 7,16, 8,6, 9,18

Estimate the values of y when the value of x is 10 and also estimate the value of x when the value of y is 5.

HARD
12th ICSE
IMPORTANT

The following table shows the ages x and systolic blood pressure y of 12 women.

Find the correlation coefficient between x and y. (Answer upto two places of decimal)

Age (x) 56 42 72 36 63 47 55 49 38 42 68 60
Blood Pressure (y) 147 125 160 118 149 128 150 145 115 140 152 155
 

 

EASY
12th ICSE
IMPORTANT

The following table shows the ages x and systolic blood pressure y of 12 women.

Determine the least squares regression line of y on x.

Age (x) 56 42 72 36 63 47 55 49 38 42 68 60
Blood Pressure (y) 147 125 160 118 149 128 150 145 115 140 152 155
 

 

EASY
12th ICSE
IMPORTANT

The following table shows the ages x and systolic blood pressure y of 12 women.

Estimate the blood pressure of a woman whose age is 45 years.

Age (x) 56 42 72 36 63 47 55 49 38 42 68 60
Blood Pressure (y) 147 125 160 118 149 128 150 145 115 140 152 155