ramona's garage charges the following labor rates. all customers are charged for at least 0.5 hr.

ramona's garage
hours
0.5
1
1.5
2
2.5
labor
$60
$90
$120
$150
$180

a. write a linear function for the data in the table.
b. a repair job took 4 hr and 15 min and required $390 in parts. what is the total cost?

a. The linear function is given by,

y = 60x + 30  [y is in $ and x is in hour and x ≥ 0.5]

  = 60 [for x < 0.5]

b. The total cost of the repair job is,  $ 675 .

Step-by-step explanation:

Let, the linear function describing garage charge( y in $) and no. of hours of repair job ( x in hour) be,

y = mx + c    [for x ≥ 0.5]  -----------(1)

where, m is the slope of the line and c is the y intercept.

Now ,

m =

  = 60  ----------------(2)

Now, putting the value of m and the point (x,y) = (0.5, 60) in (1), we get,

$

⇒ c = 30 ----------------- (3)  

Hence, the linear function is given by,

y = 60x + 30  [y is in $ and x is in hour and x ≥ 0.5] ------------(4)

  = 60 [for x < 0.5]

Now, putting

x = 4 hr 15 min

= hour

= 4.25 hour in (4), we get,

 [in $]

= $ 285

So, the total cost of the repair job,

= $ (285 + 390)

= $ 675

4

step-by-step explanation: