Answer:
Step-by-step explanation:
Given that an advertiser wishes to estimate the proportion of adults in Utah who already own a gym membership.
Confidence level wanted = 90%
Critical value Z for 90% = 1.645
p is not known hence for maximum std error we know p =0.5
Let us take p =0.5
Margin of error = [tex]1.645*\sqrt{\frac{pq}{n} } =\\1.645*0.5(\frac{1}{\sqrt{n} } ) 0.10\\n=67.65\\n~68[/tex]
Sample size can be 68