Answer:
approximately 7 hours
see the explanation
Step-by-step explanation:
The picture of the question in the attached figure
Let
x ----> the time worked in hours
y ----> the amount earning in dollars
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form [tex]k=\frac{y}{x}[/tex] or [tex]y=kx[/tex]
In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin
so
In this problem we have a proportional relationship
step 1
Find approximately how many hours would it take Delia to earn $250 ?
Looking at the graph
For y=$250 The value of x is approximately 7 hours
see the attached figure N 2
step 2
Find the exact value
from the graph take the point (5,175)
Find the value of k
[tex]k=\frac{y}{x}[/tex] ----> [tex]k=\frac{175}{5}=\$35\ per\ hour[/tex]
The linear equation is
[tex]y=35x[/tex]
For y=$250
substitute
[tex]250=35x[/tex]
solve for x
[tex]x=7.14\ hours[/tex]
