# Math Help - Linear Cosrt Functions

1. ## Linear Cosrt Functions

**cost
Could someone break this down Barney style for me?

The manager of a frozen Air Referigerator factory notices that on Monday it costs the company a total of $25,000 to build 30 referigerators and on Tuesday ot cost$30,000 to build 40 referigerators.

(a) Find a linear cost function based on this information

when I think linear cost function i want to put it in this form
c(x) = marginal cost(x) + Fixed cost

soo.. do I multiply 25000*30=750,000
then... 30,000*40=1,200,000

then i get stuck!

(b) What is the daily fixed cost?

2. Originally Posted by johnewton
**cost
Could someone break this down Barney style for me?

The manager of a frozen Air Referigerator factory notices that on Monday it costs the company a total of $25,000 to build 30 referigerators and on Tuesday ot cost$30,000 to build 40 referigerators.

(a) Find a linear cost function based on this information

when I think linear cost function i want to put it in this form
c(x) = marginal cost(x) + Fixed cost

soo.. do I multiply 25000*30=750,000
then... 30,000*40=1,200,000

then i get stuck!

(b) What is the daily fixed cost?
two points ... (x, c(x))

(30, 25000) and (40, 30000)

slope ... $m = \frac{30000 - 25000}{40 - 30} = 500$

point-slope form ...

$c(x) - 25000 = 500(x - 30)$

$c(x) = 500x + 10000$

fixed cost = 10000