Answer:
[tex]y=120 * 1.1^x[/tex] --- function
The monthly rate is 10%
Step-by-step explanation:
Given
Let
[tex]x \to months[/tex]
[tex]y \to mice[/tex]
So, we have:
[tex](x_1,y_1) = (0,120)[/tex] --- Monday
[tex](x_2,y_2) = (1,132)[/tex] --- One month later
Required
The function
The function is represented as:
[tex]y=ab^x[/tex]
In [tex](x_1,y_1) = (0,120)[/tex], we have:
[tex]120 = a * b^0[/tex]
[tex]120 = a * 1[/tex]
[tex]120 = a[/tex]
[tex]a=120[/tex]
In [tex](x_2,y_2) = (1,132)[/tex], we have:
[tex]132 = a * b^1[/tex]
[tex]132 = a * b[/tex]
Substitute: [tex]a=120[/tex]
[tex]132 = 120 * b[/tex]
Solve for b
[tex]b = \frac{132}{120}[/tex]
[tex]b = 1.1[/tex]
So, the function is:
[tex]y=ab^x[/tex]
[tex]y=120 * 1.1^x[/tex]
To calculate the monthly rate (r), we have:
[tex]y =a(1 + r)^x[/tex]
Compare to: [tex]y =ab^x[/tex]
[tex]1 + r = b[/tex]
Make r the subject
[tex]r = b-1[/tex]
Substitute [tex]b = 1.1[/tex]
[tex]r = 1.1-1[/tex]
[tex]r = 0.1[/tex]
Express as percentage
[tex]r = 0.1*100\%[/tex]
[tex]r = 10\%[/tex]
