21. a. Biology The table shows how the number of cricket chirps per minute changes with the air temperature.
40
50
60
70
80
90
Temperature (°F)
Chirps per minute
o
40
B0
120
160
200
Find the rates of change,
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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

the answer is b. 60. each interior angle in 120, so the exterior angle must be 60 in order to add up to 180

step-by-step explanation: