Answer
Graphically: $1964$
Algebraically: $1964$
Work Step by Step
From the graph as shown, at $t=70.1$, $y\approx24$. Then, the year is:
$$y=1940+24=1964$$
Verifying algebraically:
$$70.1=\frac{63.6+0.97t}{1+0.01t}$$
$$70.1(1+0.01t)=63.6+0.97$$
$$70.1+0.701t=63.6+0.97t$$
$$-0.269t=-6.5$$
$$t=\frac{-6.5}{-0.269}\approx24$$
$$t=1940+24=1964$$
Thus, the answer $1964$ is verified algebraically.
