Answer
a. $21\ hrs$; overestimates 1 hour.
b. $20\ hrs$.
Work Step by Step
a. Using the given function $f(x) = -3.52 ln (x) + 34.5$, with $x=2010-1964=46$, we have $f(46) = -3.52 ln (46) + 34.5\approx21\ hrs$. The bar graph gives a value of $20$ hours; thus the function value overestimates the number by 1 hour.
b. For year $2025$, we have $x=2025-1964=61$ and $f(61) = -3.52 ln (61) + 34.5\approx20\ hrs$.
