The graphs show the percentage of jobs in the U.S. labor force held by men and by women from 1970 through $2015 .$
(GRAPH CAN NOT COPY)
The formula
$$p=1.6 \sqrt{t}+38$$
models the percentage of jobs in the U.S. labor force, $p$, held by women $t$ years after 1970 .
a. Use the appropriate graph to estimate the percentage of jobs in the U.S. labor force held by women in 2010 . Give your estimation to the nearest percent.
b. Use the mathematical model to determine the percentage of jobs in the U.S. labor force held by women in 2010 . Round to the nearest tenth of a percent.
c. According to the formula, when will $51 \%$ of jobs in the U.S. labor force be held by women? Round to the nearest year.