Question

Create a four-corner model of the following problem:A plumber charges $25 for a service call plus $50 for each hour he spends at the service call. Use the four-corner modelto write an equation, build a table, use two points to find the slope and create a graph to show the relationship.What do you think the slope and y-intercept represent?

Answer 1

Problem

Create a four-corner model of the following problem:

A plumber charges $25 for a service call plus $50 for each hour he spends at the service call. Use the four-corner model

to write an equation, build a table, use two points to find the slope and create a graph to show the relationship.

What do you think the slope and y-intercept represent?

Solution

For this case we need to create a model given by this general expression:

y= mx +b

with the info given we can find the total cost for 1 hour of service as:

y1= 50*1 + 25= 75

And for 2 hours of service:

y2= 50*2 + 25= 125

And the slope would be:

`m=(125-75)/(2-1)=50`

where m represent the slope and b the y intercept

And for this case from the info given we can conclude that m = 50 and b = 25

So then our model would be given by:

y = 50 x +25

With x= number of hours he spend for the service

And 50 represent the variable cost per each hour and 25 is the initial cost or fixed cost