Question

What was the first year that the amusement park had more than 12 million visitors?

Answer 1

Answer:

The first year that the amusement park had more than 12 million visitors is 2008.

Step-by-step explanation:

Given:

$y=4.2\sqrt{0.28x-1}$

As per the question, the number of visitors must be greater than 12 million.

So, $y>12$

Plug in $4.2\sqrt{0.28x-1}$ for $y$ and solve for $x$.

$4.2\sqrt{0.28x-1}>12$

$\sqrt{0.28x-1}>\frac{12}{4.2}\\0.28x-1>(\frac{12}{4.2}) ^{2} \\0.28x>8.16+1\\x>\frac{9.16}{0.28} \\x>32.7$

Therefore, least value of $x$ for which the number of visitors are more than 12 million is $x=33$.

Since, $x$ is measured after 1975.

Therefore, the first year that the amusement park had more than 12 million visitors is $1975+x=1975+33=2008$.