Question

If Sarah works at the concession stand for 2 hours, she’ll earn $ 15.50, but if she works for 4 hours, she’ll earn $ 31. Find the rate of change ?

Answer 1

the rate of change is 7.75 dollars per hour

Explanation:

If Sarah works at the concession stand for 2 hours, she’ll earn $ 15.50,

but if she works for 4 hours, she’ll earn $ 31

For 2 hours , she earns 15.50 (2,15.50)

For 4 hours she earns 31 (4,31)

to find rate of change we apply slope formula

`slope = (y_2-y_1)/(x_2-x_1)`

`slope = (31-15.5)/(4-2)`

slope = 7.75

So the rate of change is 7.75 dollars per hour

Answer 2

$15.50/(2 h) = $7.75/h = $31.00/(4 h)

Sarah makes $7.75 per hour.

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While you might be interested in hours per dollar, the customary way to express earnings is in dollars per hour. Either is a "rate of change."