#### Answer

a. $(1,4)$ and $(8,10)$ minutes.
b. $(4,8)$ and $(10,12)$ minutes.
c. $3$
d. $4$.
e. negative
f. $117$ beats per minute, $t=10$ minutes.
g. $64$ beats per minute, $t=8$ minutes.

#### Work Step by Step

Based on the given graph, we have:
a. The woman’s heart rate increases during $(1,4)$ and $(8,10)$ minutes.
b. The woman’s heart rate decreases during $(4,8)$ and $(10,12)$ minutes.
c. There are $3$ turning points during the first 12 minutes.
d. We can determine the degree of the polynomial function of best fit as $4$.
e. The leading coefficient of the polynomial function should be negative as the end behavior is $x\to\infty, y\to-\infty$
f. Using the graph, we can estimate the woman’s maximum heart rate during the first 12 minutes to be about $117$ beats per minute, which happened at $t=10$ minutes.
g. Using the graph, we can estimate the woman’s minimum heart rate during the first 12 minutes to be about $64$ beats per minute, which happened at $t=8$ minutes.