it would take 7/10 of an hour too fill the pool.
from the figure we get,
the x axis shows the months and,
the y-axis shows the number of satisfied customer.
each line or each cell in upward direction (y-axis) shows 500.
the appropriate scale for the y - axis is: -
a = 2000 customers
b = 4000 customers
c = 6000 customers
d = 8000 customers
e = 10000 customers
f = 12000 customers
g = 14000 customers