Answer:
The best prediction for the population in year 25 is 
Step-by-step explanation:
we have a exponential function of the form

where
a is the initial value
b is the base
In this problem





so

For 
substitute


Round up

-7 + 3 + 10 = -4 + 10 = 10 - 4 = 6.
To turn 13 into 10, you need to break it up into 10 + 3, which does not change the value of 13. Then, you add 3 to -7, which results in -4. Next, you add -4 to 10 (or rather, subtract 4 from 10), which results in 6.
So to find the avrage u r going to add all the numbers then divide by the nuber of nubers u have there that will give u ur answer
Answer: B) 4
Step-by-step explanation:
Using the formula
Standard deviation = √( (Σ ( x - π)²)/n)
To get the standard deviation, first we workout the Mean which is the simple average of the data set
n = 4
(13 + 17 + 9 + 21) / 4 = 60/4 = 15
Mean(x) = 15
Then (x-π)²
13 - 15 = (-2)² = 4
17 - 15 = (2)² = 4
9 - 15 = (-6)² = 36
21 - 15 = (6)² = 36
Σ ( x - π)² = (4 + 4 + 36 + 36) = 80
Standard deviation = √( (Σ ( x - π)²)/n
= √ (80/4)
=√20
= 4.47
= 4
The answer is 1400 because he got 400$ on the third to last week, 500$ on the second to last week, and 500$ on the last week. that adds up to 1400$