Based on the size of the sample, the 95% confidence interval for American adults who believe in aliens is (0.6577719, 0.7822281).
With a 95% interval, we can find the Z score using the Z table to be 1.96.
The 95% interval here would therefore be:
Lower limit:
= (Proportion that believes in Aliens - 1.96 x √((Proportion that believes in aliens x Percentage that doesn't)) / Sample size
= 0.72 - 1.96 x √((0.72 * 28) / 200)
= 0.6577719
Upper limit:
= 0.72 + 1.96 x √((0.72 * 28) / 200)
= 0.7822281
Find out more on confidence intervals at https://brainly.com/question/16974109.
