Between 2000 and 2005, 1000 of 10,000 young women ages 17 to 20 years at a university tested positive for a sexually transmitted infection (STI). Of the 1000 diagnosed STIs, 300 were gonorrhea and 500 were chlamydia. Which of the following statements best summarizes these findings?

Question

Quizplus · Accepted Answer

A proportion is a ratio in which the denominator includes the numerator.If the proportion is small, we can express the number per 1000. The answer of 300:1300 adds the total of the numerator to the denominator, which is unnecessary because the gonorrhea cases were already included in the denominator. In the answer of 300:500, the ratio comparing gonorrhea to chlamydia does not meet the epidemiological definition of proportion (i.e., the denominator must contain the numerator). Although proportions may be expressed as percentages, in the answer of 50% the percentage reflects the number of gonorrhea cases to all STIs, which doesn't summarize the total STI problem. The answer of 100:1000 correctly summarizes that 1000 of 10,000 (or 100:1000) young women had the problem.

Between 2000 and 2005, 1000 of 10,000 Young Women Ages