Answer:
f(x)=0.17x+3.00
f(60)=0.17(60)+3.00
f(60)=10.20+3
f(60)=13.20
1 hour will cost $13.20
Explanation:
I found the difference in minutes between the given values and the difference in cost between the given values. Between 8 minutes and 25 minutes is 17, and between 25 and 40 is 15 minutes. The difference of $7.25 and $4.36 is $2.89, and the difference between $7.25 and $9.80 is $2.55. I then divided2.89 by 17 and 2.55 by 15 and both resulted in $0.17/minute. I them multiplied 8 minutes by $0.17 toget $1.36. I subtracted that from the cost given for 8 minutes to get $3.00. The $3.00 is the initial charge, or b in slope-intercept form with m=0.17. Plug in 60 for x to find the cost of an hour.