Question 206036
You are correct on part 1a)
For part b, you need to set N = 7 (for 7 million) and solve for x, (the number of years from now).
{{{7 = sqrt(x)+2}}} Subtract 2 from both sides.
{{{5 = sqrt(x)}}} Finally, square both sides.
{{{25 = x}}}
There will be 7 million cases 25 years from now.