The mean price of a pound of ground beef in 75 cities in the Midwest is $2.11 and the standard deviation is $0.56. A histogram of the data shows that the distribution is symmetrical. A local Midwest grocer is selling a pound of ground beef for $3.25. What is this price in standard units?
Assuming the Empirical Rule applies, would this price be unusual or not? Round to the nearest Hundredth.
A) $ z=2.04 $; This price would not be unusual.
B) $ z=-2.04 $; This is unusually inexpensive ground beef.
C) $ z=2.04 $; This is unusually expensive ground beef.
D) $ z=-2.04 $; This price would not be unusual.

Question

The mean price of a pound of ground beef in 75 cities in the Midwest is $2.11 and the standard deviation is $0.56. A histogram of the data shows that the distribution is symmetrical. A local Midwest grocer is selling a pound of ground beef for $3.25. What is this price in standard units?
Assuming the Empirical Rule applies, would this price be unusual or not? Round to the nearest Hundredth. 
A) $ z=2.04 $; This price would not be unusual.
B) $ z=-2.04 $; This is unusually inexpensive ground beef.
C) $ z=2.04 $; This is unusually expensive ground beef.
D) $ z=-2.04 $; This price would not be unusual.

Quizplus · Accepted Answer

The z-score is calculated as $ z = \frac{(3.25 - 2.11)}{0.56} = 2.04 $. According to the Empirical Rule, a z-score of 2.04 is more than 2 standard deviations from the mean, making it unusually expensive.

The Mean Price of a Pound of Ground Beef in 75