IMR in Singapore. The infant mortality rate (IMR) is the number of infant deaths per 1000 live births. Suppose that you have been commissioned to estimate the IMR in Singapore. From a random sample of 1109 live births in Singapore, you find that 0.361%

of them resulted in infant deaths. You next find a 90% confidence interval:

0.00361 ± 1.645 ·

(0.00361)(0.99639)/1109, or 0.000647 to 0.00657. You then conclude, “I can be 90% confident that the IMR in Singapore is somewhere between 0.647 and 6.57.”

How did you do?