Question

what is the lowest temperature and at what time did it occur?
a. 5°f at 3:00 a.m.
b. 5°f at 5:00 a.m.
c. 15°f at 3:00 a.m.
d. 15°f at 5:00 a.m.

Explanation:

Step1: Identify lowest graph point

The curve's lowest point is at $h=5$, with temperature $15^\circ\text{F}$.

Step2: Calculate corresponding time

Start time is 10:00 p.m. Add 5 hours: $10:00\text{ p.m.} + 5\text{ h} = 3:00\text{ a.m.}$

Answer:

C. $15^\circ\text{F}$ at 3:00 a.m.