Soru

Zorluk: OrtaLinear Equations and Graphing

A custom printing company uses a linear relationship to determine the total cost of printing t-shirts. The table below displays the total cost, CC, in dollars, for printing xx t-shirts:

Number of Shirts (xx)Total Cost (CC)
15\$162.50
25\$237.50
35\$312.50

If the total cost consists of a one-time setup fee plus a constant charge per t-shirt, what is the one-time setup fee?

  1. A
    \$7.50
  2. B
    \$10.83
  3. C
    \$12.50
  4. \$50.00Cevap
  5. E
    \$112.50

Cevap

The one-time setup fee is \$50.00.
The correct answer of \50.00isfoundbyfirstdeterminingtheconstantrateofchange(slope)fromthetable,whichis$7.50pershirt.Substitutingthisrateandthedatapointfor15shirtsintothelinearmodel50.00 is found by first determining the constant rate of change (slope) from the table, which is \$7.50 per shirt. Substituting this rate and the data point for 15 shirts into the linear model C = mx + b gives gives 162.50 = 7.50(15) + b .Solvingfortheyintercept. Solving for the y-intercept b yields yields 50.00, which represents the one-time setup fee.

Adım Adım Çözüm

1
Calculate the constant charge per t-shirt (the slope, mm) by finding the change in cost divided by the change in the number of shirts between two data points.
m=237.50162.502515=75.0010=7.50m = \frac{237.50 - 162.50}{25 - 15} = \frac{75.00}{10} = 7.50
Since the relationship is linear, the rate of change (cost per shirt) remains constant.
2
Write the linear equation representing the total cost: C=7.50x+bC = 7.50x + b, where bb represents the one-time setup fee.
C=7.50x+bC = 7.50x + b
This sets up the slope-intercept form of the linear relationship.
3
Substitute one of the points from the table, such as (15,162.50)(15, 162.50), into the equation to solve for bb.
162.50=7.50(15)+b162.50 = 7.50(15) + b
162.50=112.50+b162.50 = 112.50 + b
b=50.00b = 50.00
Using a known coordinate point allows us to isolate and solve for the unknown y-intercept (the setup fee).

Anahtar Kavram

Linear Equations and Graphing
Bu soruyu puanla