## Problems on Curve Fitting

**Problems on Curve Fitting:**

**Example-1** Fit straight line for the following data:

**Solutions:** Let straight line is a bx. Normal equation for straight lines are

Form the following table

Now normal equations reduces to

On solving, a = −1.1381 and b = 2.8966

Hence the fitted straight line is

y = −1.1381 2.8966x

**Example-2** Fit a straight line to the following data :

**Solutions:** Here n = 6, i.e., even and the values of x are equally spaced , h is equal to 5. Therefore, to make the calculation easier, we take the unit of measurement h/2 , i.e., 2.5 and the origin at the mean of two middle terms 10 and 15, i.e., origin is taken at 1/2 (10 15) = 12.5.

Let the equation of straight line be

v = a bu

Then the normal equation are

So,

Thus, the required equation of straight line is

y = 0.7x 11.285