91Ó°ÊÓ

• Richard's Heating and Cooling charges $\$55$per hour plus a $\$30$service charge.
• The y-intercept is $\$30$.
• The slope is $\$55$.
• Let x denote the number of hours required for a job, and
• Let y denote the total cost to the customer.

The regression equation is $y=b_0+b_{1}x$

Where,

$b_0=y$-intercept

$b_1=$slope

x = independent variable.

y = dependent variable.

The regression equation y in terms of x is: $y=30+55x$

The regression equation is $y=30+55x$

The y-intercept, $b_0=30$

The slope, $b_1=55$

We construct the table for the x-values 0.5,1 and 2.25 as shown below:

The graph for the equation $\hat{y}=30+55x$:

From the graph, we can see that the estımated cost of the job that takes $1.15$hours is $\$125.5$. The exact cost of the job that takes $1.75$ hours is

$$\begin{gathered} \hat{y}=30+55x \\ =30+55(1.75) \\ =126.25 \end{gathered}$$