Refer to the following paragraph to answer the questions below.
The infant mortality rate (number of infants who die in their first year per 1,000 births) has a mean for the OECD (most advanced industrial countries) of 8 with a standard deviation of 1.
-The infant mortality rate in the U.S. is 9 infant deaths per 1,000 births. The rate for Ireland, Singapore, Hong Kong, Netherlands, France, Canada, Germany, and Switzerland are all the same. Their rate is 2 z-scores below that of the U.S. What is their rate?

Question

Refer to the following paragraph to answer the questions below. 
The infant mortality rate (number of infants who die in their first year per 1,000 births) has a mean for the OECD (most advanced industrial countries) of 8 with a standard deviation of 1.
-The infant mortality rate in the U.S. is 9 infant deaths per 1,000 births. The rate for Ireland, Singapore, Hong Kong, Netherlands, France, Canada, Germany, and Switzerland are all the same. Their rate is 2 z-scores below that of the U.S. What is their rate?

Quizplus · Accepted Answer

The U.S. has an infant mortality rate of 9. Being 2 z-scores below this means subtracting 2 times the standard deviation (2 * 1 = 2) from the U.S. rate. Therefore, 9 - 2 = 7 is the rate for the mentioned countries.

Refer to the Following Paragraph to Answer the Questions Below