Adele Is Studying a New Species of Insect That Emits

Multiple Choice

$$\begin{array} { | l | l | } \hline \text { Length (inch) } & \text { Frequency } \\\hline 0.1 & 2 \\\hline 0.2 & 3 \\\hline 0.3 & 3 \\\hline 0.4 & 5 \\\hline 0.5 & 4 \\\hline 0.6 & 2 \\\hline 0.7 & 2 \\\hline\end{array}$$ 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.
Adele discovers a new specimen of this insect species. It is 0.5 inches long. What is its z-score?

A) 0.50
B) 0.61
C) 0.71
D) 0.80