A(n) is things that are together.

equation

lesson

estimate

group

This is a pretty easy question for me but I'm thinking not for you.

The answer is group and if you need more help:

A group is a number of people or things that are located, gathered, or classed together.

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