Question

During routine screening a doctor notices that 18% of her adult patients show higher than normal levels of glucose in their blood ---- a possible warning signal for diabetes. Hearing this, some medical researchers decide to conduct a large-scale study, hoping to estimate the proportion to within 5% with 95% confidence. How many randomly selected adults must they test?

The number of adults that should be tested is ____.

Answer 1

Sample size = Z²/2 * p (1 - p) / E²

= 1.96² * 0.18 * 0.82 / 0.05²

= 226.81

Sample size = 227 (Rounded up to nearest integer)