Chapter 15.3, Problem 14E

A hygrothermograph is used by the weather services to record temperature and relative humidity (see Illustration 5). The lower part of the graph is used to measure relative humidity from 0% to 100%. The upper part of the graph is used to measure temperature from $10°$

F to $110°$

F. For example, at 8:00 P.M., the temperature was $86°$

F, and the relative humidity was 82%.

ILLUSTRATION 5

Hygrothermography (temperature in $°\text{F}$ and relative humidity in %)

Use the hygrothermograph in Illustration 5 to answer Exercises 9–14.

What was the lowest relative humidity recorded?