Weights of females have approximately a normal distribution with mean 135 lbs. and standard deviation 20 lbs. Allison weighs 145 lbs. What is the z-score for her weight?
A) 10
B) 1.50
C) 0.50
D) 0.20

Question

Quizplus · Accepted Answer

The z-score is calculated by subtracting the mean from the individual score and then dividing by the standard deviation: $z = \frac{(X - \mu)}{\sigma}$. For Allison, $z = \frac{(145 - 135)}{20} = \frac{10}{20} = 0.50$.

Weights of Females Have Approximately a Normal Distribution with Mean