Cancer A case-control study of the effectiveness of the Pap smear in preventing cervical cancer (by identifying precancerous lesions) was performed [1]. It was found that 28.1% of 153 cervical-cancer cases and 7.2% of 153 age-matched (within 5 years) controls had never had a Pap smear prior to the time of the case's diagnosis. 6.5 6.6 6.7 Provide a 95% CI for the percentage of cervical-cancer cases who never had a Pap test. Provide a 95% CI for the percentage of controls who never had a Pap test. Do you think the Pap test is helpful in preventing cervical cancer?