Answer:
The function is:
![y = 68 (1.5) ^ x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gem3lalr3auanxoy6njhycnmoiyhd9g9tr.png)
Explanation:
Note that the number of people increases by a factor of 1.5 per hour, and the initial number of people is 68.
So:
After an hour the number of people is:
![y = 68 (1.5)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/vmx6ql6holec1v3ru8xv2i5p2vl35yhmu3.png)
After two hours the number of people is:
![y = 68 (1.5) (1.5) = 68 (1.5) ^ 2](https://img.qammunity.org/2020/formulas/mathematics/middle-school/e6p5lv1etgqolq4jund03mz7wigcpsshqu.png)
After x hours the number of people is:
![y = 68 (1.5) ^ x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gem3lalr3auanxoy6njhycnmoiyhd9g9tr.png)
Therefore, the exponential growth function that models the number of people y at the fair after x hours is:
![y = 68 (1.5) ^ x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gem3lalr3auanxoy6njhycnmoiyhd9g9tr.png)