$$\begin{array} { | l | l | }
\hline \text { Length (inch) } & \text { Frequency } \
\hline 0.1 & 2 \
\hline 0.2 & 3 \
\hline 0.3 & 3 \
\hline 0.4 & 5 \
\hline 0.5 & 4 \
\hline 0.6 & 2 \
\hline 0.7 & 2 \
\hline
\end{array}$$ Adele is studying a new species of insect that emits an odor perceived to be pleasant to humans. The known population consists of 21 insects. Adele has measured the length of each one.
What is the population mean?
A) 0.3
B) 0.4
C) 0.5
D) 0.6

Question

$$\begin{array} { | l | l | } 
\hline \text { Length (inch) } & \text { Frequency } \
\hline 0.1 & 2 \
\hline 0.2 & 3 \
\hline 0.3 & 3 \
\hline 0.4 & 5 \
\hline 0.5 & 4 \
\hline 0.6 & 2 \
\hline 0.7 & 2 \
\hline
\end{array}$$ Adele is studying a new species of insect that emits an odor perceived to be pleasant to humans. The known population consists of 21 insects. Adele has measured the length of each one.
What is the population mean?
A) 0.3
B) 0.4
C) 0.5
D) 0.6

Quizplus · Accepted Answer

To find the population mean, we need to find the sum of all the lengths and divide by the total number of insects. 
Sum of lengths = (0.1 x 2) + (0.2 x 3) + (0.3 x 3) + (0.4 x 5) + (0.5 x 4) + (0.6 x 2) + (0.7 x 2) = 11.2
Total number of insects = 21
Population mean = 11.2/21 = 0.533, which is closest to 0.4. Therefore, the answer is B) 0.4.

Adele Is Studying a New Species of Insect That Emits