Chapter 4.2, Problem 80E

Physiology

Doctors treated a patient at an emergency room from $2:00\text{ P}\text{.M}\text{. to }7:00\text{ P}\text{.M}\text{.}$. The patient’s blood oxygen level $L$ (in percent form) during this time period can be modeled by

$L=-0.270t^2+3.59t+83.1,2\le t\le 7$

where $t$ represents the time of day, with $t=2$ corresponding to $2:00\text{ P}\text{.M}\text{.}$. Use the model to estimate the time (rounded to the nearest hour) when the patient’s blood oxygen level was $93\%$.