Answer:

Step-by-step explanation:
We can write this rate as an ordinary differential equation.

Where a is proportional constant, P the population variable, and t the time.

Integrating each side of the equation.



To find C we need to use the initial condiction, it means evaluae P at t=0.


Now, we use the sentence the population has doubled in 5 years.

We can find "a" in this condition.




Finally, let's find how long will it take to triple.




I hope it helps you!
Answer:
40
Step-by-step explanation:
34% of the scores lie between 433 and 523.
Solution:
Given data:
Mean (μ) = 433
Standard deviation (σ) = 90
<u>Empirical rule to determine the percent:</u>
(1) About 68% of all the values lie within 1 standard deviation of the mean.
(2) About 95% of all the values lie within 2 standard deviations of the mean.
(3) About 99.7% of all the values lie within 3 standard deviations of the mean.



Z lies between o and 1.
P(433 < x < 523) = P(0 < Z < 1)
μ = 433 and μ + σ = 433 + 90 = 523
Using empirical rule, about 68% of all the values lie within 1 standard deviation of the mean.
i. e. 
Here μ to μ + σ = 
Hence 34% of the scores lie between 433 and 523.
Selling price of app per user = $10 per month
Total no. of user in first month = 10
To tal no. of user added per month = 7
We have to find how much money is earned in one year
So the formula is n/2 * (2a +(n-1)d)
Here we have n = 12 which is total no. of months
a = 100 , which is money earned in one month
d = 70 , which is increase in money earned per month
So money earned in a year comes out to be 5820