Answer
Age groups 58 and 33 are expected to satisfy the conditions on the exercise, which seems to be somewhat in agreement with the data on the graph.
Work Step by Step
To answer this exercise, we must find the solutions of $x$ when $N = 3$: $$3 = 0.013x^2 - 1.19x + 28.24$$
$$0 = 0.013x^2 - 1.19x + 28.24 - 3$$
$$0 = 0.013x^2 - 1.19x + 25.24 $$which is a quadratic equation that can now be solved by using the Quadratic Formula $x = \frac{-b\frac{+}{} \sqrt {b^2 - 4ac}}{2a}$:
$$x = \frac{-(-1.19)\frac{+}{} \sqrt {(-1.19)^2 - 4(0.013)(25.24)}}{2(0.013)}$$
$$x = \frac{1.19\frac{+}{} \sqrt {0.10362}}{0.026}$$
$$x \approx \frac{1.19\frac{+}{} 0.322}{0.026}$$
$$x \approx 58.15$$ $$and$$ $$x \approx 33.3846$$
