
Show that if five students get respectively marks () out of in subject , and marks () out of in subject , the regression equation of on can be written as

Important Questions on Linear Regression
Fit a straight line to the following data, treating as the dependent variable :
Hence, predict the value of when

Treating as independent variable, find the line of best fit for the following data:
Hence, predict the value of when

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

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 () | Cost per unit () |
Find the correlation coefficient. Also determine the two regression equations.

The following observations are given :
Estimate the values of when the value of is and also estimate the value of when the value of is

The following table shows the ages and systolic blood pressure of women.
Find the correlation coefficient between and . (Answer upto two places of decimal)
Age () | ||||||||||||
Blood Pressure () |

The following table shows the ages and systolic blood pressure of women.
Determine the least squares regression line of on .
Age () | ||||||||||||
Blood Pressure () |

The following table shows the ages and systolic blood pressure of women.
Estimate the blood pressure of a woman whose age is years.
Age () | ||||||||||||
Blood Pressure () |
