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In: Statistics and Probability

About 90% of young adult Internet users (ages 18 to 29) use social-networking sites. (a) Suppose...

About 90% of young adult Internet users (ages 18 to 29) use social-networking sites.

(a) Suppose a sample survey contacts an SRS of 1600 young adult Internet users and calculates the proportion pˆp^ in this sample who use social-networking sites.

What is the approximate distribution of pˆp^?

μpˆμp^ (±±0.00001) = , σpˆσp^ (±±0.00001) =

What is the probability that pˆp^ is between 87% and 93%? This is the probability that pˆp^ estimates pp within 3%.

(Use software.)

P(0.87<pˆ<0.93)P(0.87<p^<0.93) (±±0.0001) =

(b) If the sample size were 6400 rather than 1600, what would be the approximate distribution of pˆp^?

μpˆμp^ (±±0.00001) = , σpˆσp^ (±±0.00001) =

What is the probability that pˆp^ is between 87% and 93%? This is the probability that pˆp^ estimates pp within 3%.

(Use software.)

P(0.87<pˆ<0.93)P(0.87<p^<0.93) (±±0.0001) =

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