Question

A poll of 1500 college students asked whether or not they had used the Internet to find a place to live sometime within the past year. There were 525 students who answered “Yes”; the other 975 answered “No”.
a)What is n? What is the value of X? Find the sample proportion pˆ .

d)Can we use normal approximation for this sample?

e)What normal model are you using X or Pˆ ? Please find the mean and standard deviation appropriately.

f) Sketch the sampling model, using the 68-95-99.7 Rule.

Answer 1

a) n = 1500

X is the number of college students who answered Yes that they used the Internet to find a place to live sometime within the past year.

X = 525

sample proportion =

d) Yes we can use the normal model for this approximation as the poll is a success and failure trial, where

probability of success is the probability that college students answered Yes that they used the Internet to find a place to live sometime within the past year.

p = 0.35

number of trials = n = 1500

e) Here we will be using central limit theorem for proportion

f)

68% is the area between one standard deviation away from mean

95% is the area between two standard deviation away from mean

99.7% is the area between three standard deviation away from mean