Reference no: EM132857359

According to a recent? survey, 75?% of teens ages? 12-17 in a certain country used social networks in 2009. A random sample of 130 teenagers from this age group was selected. Complete parts a through d below.

a. Calculate the standard error of the proportion. σp=

?(Round to four decimal places as? needed.)

b. What is the probability that less than 77?% of the teens from this sample used social? networks? ?P(Less than 77?% of the teens from this sample used social ?networks)= ?(Round to four decimal places as? needed.)

c. What is the probability that between? 70% and? 80% of the teens from this sample used social? networks? ?P(Between 70% and? 80% of the teens from this sample used social ?networks)= ?(Round to four decimal places as? needed.)

d. What impact would changing the sample size to 200 teens have on the results of parts? a, b, and? c? Choose the correct answer below.

A. The standard error would be? reduced, which? would, in? turn, increase the probabilities that the sample proportions will be closer to the population proportion.

B. The standard error would be? reduced, which? would, in? turn, reduce the probabilities that the sample proportions will be closer to the population proportion.

C. The standard error would be? increased, which? would, in? turn, reduce the probabilities that the sample proportions will be closer to the population proportion.

D. The standard error would be? increased, which? would, in? turn, increase the probabilities that the sample proportions will be closer to the population proportion.

E. Changing the sample size would have no effect on the standard error or the probabilities that the sample proportions will be closer to the population proportion.