The common cricket can be used as a crude thermometer. The colder the temperature, the slower the rate of chirping. The table below shows the average chirp rate of a cricket at various temperatures
$\begin{array}{cc}
\hline \begin{array}{c}
\text { Chirp Rate } \
\text { (chirps/second) }
\end{array} & \begin{array}{c}
\text { Temperature } \
\left({ }^{\circ} \mathrm{F}\right)
\end{array} \
\hline 3.4 & 74 \
3.1 & 61.3 \
1.9 & 45.7 \
1.0 & 35.4 \
1.4 & 49 \
2.5 & 66 \
\hline
\end{array}$
The least-squares regression line for predicting the temperature from the chirp rate is $y = 24.3278 + 13.9423 x$. If two chirp rates differ by $1.5$ chirps per second, by how much would the temperature differ?
A) $21 ^ { \circ } \mathrm { F }$
B) $24 ^ { \circ } \mathrm { F }$
C) $36 ^ { \circ } \mathrm { F }$
D) $20 ^ { \circ } \mathrm { F }$

Question

Quizplus · Accepted Answer

The temperature difference for a 1.5 chirps per second difference in chirp rate can be calculated using the slope of the regression line, which is 13.9423. Multiplying this slope by the chirp rate difference gives $13.9423 \times 1.5 = 20.91345$, which rounds to approximately $21 ^{\circ}F$.

The Common Cricket Can Be Used as a Crude Thermometer