Gina and Stewart are surf-fishing on the Atlantic coast, where both bluefish and pompano are common catches. The mean length of a bluefish is 264 millimeters with a standard deviation of $41 \mathrm {~mm}$. For pompano, the mean is $146 \mathrm {~mm}$ with a standard deviation of $24 \mathrm {~mm}$.
Stewart caught a bluefish that was $355 \mathrm {~mm}$ long. What was the $z$-score for this length?
A) 8.66
B) 355
C) 8.71
D) 2.22

Question

Quizplus · Accepted Answer

The $z$-score is calculated by subtracting the mean from the observed value and then dividing by the standard deviation. For Stewart's bluefish, $z = \frac{355 - 264}{41} = \frac{91}{41} = 2.22$.

Gina and Stewart Are Surf-Fishing on the Atlantic Coast, Where 41 mm41 \mathrm {~mm}41 mm

Gina and Stewart Are Surf-Fishing on the Atlantic Coast, Where $41 \mathrm {~mm}$