USA Today reported the results of a survey conducted by HarrisInteractive to determine the percentage of adults who use a computer to access the Internet (from work, home, or other locations). The newspaper indicated the survey revealed that 74% of adults use a computer to access the Internet. The file titled Online produces a representative sample of the data collected by USA Today.
a. Calculate the sample proportion of adults who connect to the Internet using a computer.
b. If the Harris poll’s estimate of the proportion of adults using the Internet is correct, determine the sampling error for the sample in the Online file.
c. Determine the probability that a sample proportion would be at most as far away as the Online sample if the Harris poll’s estimate was correct.
d. The Harris poll indicated that its sample had a margin of error of ± 2, . The sample size used by the Harris poll was 2,022. Calculate the probability that the sample proportion from a sample size of 2,022 would be at most as far away from the population proportion as suggested by the margin of error.