Find the z-score corresponding to the given value and use the z-score to determine whether the value is unusual. Consider a score to be unusual if it is at least three standard deviations above or Below the mean. Round the z-score to one decimal place, if necessary. A weight of 238 pounds among a population having a mean weight of 162 pounds and a standard
Deviation of 25.3 pounds.
A)75.9; unusual
B)3; not unusual
C)-3; not unusual
D)3; unusual

Question

Find the z-score corresponding to the given value and use the z-score to determine whether the value is unusual. Consider a score to be unusual if it is at least three standard deviations above or Below the mean. Round the z-score to one decimal place, if necessary. A weight of 238 pounds among a population having a mean weight of 162 pounds and a standard
Deviation of 25.3 pounds. 
A)75.9; unusual
B)3; not unusual
C)-3; not unusual
D)3; unusual

Quizplus · Accepted Answer

The z-score is calculated by subtracting the mean from the given value and then dividing by the standard deviation: $z = \frac{238 - 162}{25.3} = 3$. A z-score of 3 means the value is 3 standard deviations above the mean, which is considered unusual.

Find the Z-Score Corresponding to the Given Value and Use