Answer:
[tex]2.50[/tex]
Step-by-step explanation:
Given
[tex](x_1,y_1) = (-1,0.8)[/tex]
[tex](x_2,y_2) = (0,2)[/tex]
[tex](x_3,y_3) = (1,5)[/tex]
[tex](x_4,y_4) = (2,12.5)[/tex]
Required
The rate of change (b)
The above graph is represented as:
[tex]y = ab^x[/tex]
For: [tex](x_2,y_2) = (0,2)[/tex];
We have:
[tex]y = ab^x[/tex]
[tex]2 = a * b^0[/tex]
[tex]2 = a *1[/tex]
[tex]2 = a[/tex]
[tex]a = 2[/tex]
For [tex](x_3,y_3) = (1,5)[/tex],
We have:
[tex]y = ab^x[/tex]
[tex]5 = a * b^1[/tex]
[tex]5 = a * b[/tex]
Substitute [tex]a = 2[/tex]
[tex]5 = 2 * b[/tex]
Divide by 2
[tex]2.5 = b[/tex]
[tex]b = 2.5[/tex]
Hence, the rate of change is 2.50