The average rate of change is given by [f(b) - f(a)]/(b - a), where a and b represent the interval [a, b].
Let a = -2
Let b = -1
[(-1)^2 + 10 - ((-2)^2 + 10)]/(-1 -(-2))
[1 + 10 - (4 + 10)]/(-1 + 2)
[1 + 10 -4 -10]/(1)
[1 - 4]/(1)
-3/1
Answer: -3
I'm going to convert all the values given to you in percentages, so hopefully you should be able to see the correct answer a little clearer. :)
Debbie said that 21/50 drink coffee in the morning. 21/50 can also be written as 42/100, and now that it's out of 100, it's basically a percentage. (42%).
Allen said that 45% of people drink coffee in the morning. His value is already written as a percentage, so we won't do anything with it.
Benny says that 0.495 of the people he surveyed drink coffee in the morning. 0.495 is the same as 49.5% (multiply it by 100 to get it in a percentage).
So, in Debbie's survey, 42% of people drink coffee.
In Allen's survey, 45% of people drink coffee.
In Benny's survey, 49.5% of people drink coffee.
Therefore, the answer is Benny's survey. :)
Answer:
C. N = 400 / 10
Step-by-step explanation:
Lawn-cutting Bank Account = $325
Amount paid for gas = $75
Total amount earned = Lawn-cutting Bank Account + Amount paid for gas
= $325 + $75
= $400
Amount earned per every lawn he mowed = $10
How Many Lawns Did He mow?
Let N = number of lawns he mowed
N = Total amount earned / Amount earned per every lawn he mowed
N = 400 / 10
N = 40 lawns
2 3/4a=19 1/4
÷2 3/4 ÷2 3/4
a=1/7