Question

A population of mice is increasing exponentially. On Monday there were 120 most. One month later there were 132 most. Ready function tomorrow the situation. Determine the percent increase of the population of most of each month.

Answer 1

`y=120 * 1.1^x` --- function

The monthly rate is 10%

Explanation:

Given

Let

`x \to months`

`y \to mice`

So, we have:

`(x_1,y_1) = (0,120)` --- Monday

`(x_2,y_2) = (1,132)` --- One month later

Required

The function

The function is represented as:

`y=ab^x`

In
`(x_1,y_1) = (0,120)`, we have:

`120 = a * b^0`

`120 = a * 1`

`120 = a`

`a=120`

In
`(x_2,y_2) = (1,132)`, we have:

`132 = a * b^1`

`132 = a * b`

Substitute:
`a=120`

`132 = 120 * b`

Solve for b

`b = (132)/(120)`

`b = 1.1`

So, the function is:

`y=ab^x`

`y=120 * 1.1^x`

To calculate the monthly rate (r), we have:

`y =a(1 + r)^x`

Compare to:
`y =ab^x`

`1 + r = b`

Make r the subject

`r = b-1`

Substitute
`b = 1.1`

`r = 1.1-1`

`r = 0.1`

Express as percentage

`r = 0.1*100\%`

`r = 10\%`