Q3.

OPEN ENDED Write a different prediction equation for the data in Examples 1 and 2 on pages 81 and 82.

Verified

Answer

A different predicted equation for example 1 is $y = 5 x + 110$

1Step-1 – Write information from example 1 and 2

The table below shows the median selling price of new, privately-owned, one-family houses for some recent years.

Except for (0, 122.9), the data appear to lie nearly on a straight line.

2Step-2 – Find slope for line

Taking points (4, 130) and (6, 140)

Slope = $\frac{140 - 130}{6 - 4}$ $[∵ Slope = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}]$

$\begin{array}{l} = \frac{10}{2} \\ = 5 \end{array}$

3Step-3 – Using point-slope form

Point slope form : $(y - y_{1}) = m (x - x_{1})$

Substituting values

$\begin{array}{l} (y - 130) = 5 (x - 4) \\ y = 5 x + 110 \end{array}$

Hence, a different predicted equation for example 1 and 2 is $y = 5 x + 110$