2- Mobile phones
The graph shows the number of calls (n) Pete made on his mobile
phone each month last
year and his bill (£b) for the month.
Cost (£b)
60
50
40
30
丼丼
20
10
0
20
Calls(n)
40
60
Write down the equation
of the line of best fit.
b =
0.4n+22
What is the average cost of
each extra call Pete makes?
Cost =
pence
Estimate how much Pete would pay
in a month when
he made 40 calls.
Cost = £37