Question

The cost of internet access at a café is a function of time. The costs for 8, 25, and 40 minutes are shown. Write an equation in slope-intercept form that represents the function. Then find the cost of surfing the web at the café for one hour. Time (min) 8 25 40 Cost ($) 4.36 7.25 9.80

Answer 1

Answer:

• $y=0.17x+3$
• The cost of surfing the web at the café for one hour: $\ 13.2$

Step-by-step explanation:

The equation of the line in Slope-Intercept form is:

$y=mx+b$

Where "m" is the slope and "b" is the y-intercept.

Take two points and substitute them into the formula for calculate the slope (The formula is $m=\frac{y_2-y_1}{x_2-x_1}$).

Having these points:

$(8,4.36)$ and $(40,9.80)$

You can identify that:

$y_2=4.36\\y_1=9.80\\\\x_2=40\\x_1=8$

Then, the slope is:

$m=\frac{4.36-9.80}{40-8}=0.17$

Substitute the slope and the coordinates of any point on the line into the equation $y=mx+b$ and then solve for "b":

$4.36=0.17(8)+b\\\\4.36-1.36=b\\\\b=3$

Therefore, equation in Slope-Intercept form that represents the function is:

$y=0.17x+3$

Since 1 hour hour has 60 minutes, you need to substitute $x=60$ into the equation and then evaluate, in order to find the cost of surfing the web at the café for one hour. Then:

$y=0.17(60)+3\\\\y=13.2$