phthalates are present in many diverse products, including insect repellents, body lotions, perfumes, and food packaging. Because animal experiments suggest that phthalates may have an adverse effect on the male reproductive system, a group of infertility specialists decided to conduct a case-control study on phthalate exposure and sperm abnormalities in adult men. 100 cases with sperm abnormalities and 100 controls were identified and enrolled from among patients at their infertility clinic. 30 cases and 10 controls had high urinary phthalate levels. the remainder had normal urinary phthalate levels.

set up and fill in the two by two table using data

use these data to calculate the odds ratio describing the relationship between phthalate levels and sperm abnormalities