Question

A survey of 120 students is selected randomly on a large university campus. They are asked if they use a laptop in class to take notes. The result of the survey is that 60 of the 120 students responded "yes." An approximate 98% confidence interval is (0.394,0.606). Complete parts a through d below. a) How would the confidence interval change if the confidence level had been 90% instead of 98% ? The new confidence interval would be The new confidence interval would be (Round to three decimal places as needed.) b) How would the confidence interval change if the sample size had been 300 instead of 120 ? (Assume the same sample proportion.) The new confidence interval would be The new confidence interval would be I (Round to three decimal places as needed.) c) How would the confidence interval change if the confidence level had been 99% instead of 98% ? The new confidence interval would be The new confidence interval would be I (Round to three decimal places as needed.) d) How large would the sample size have to be to make the margin of error half as big in the 98% confidence interval? The new sample size would have to be

Answer 1

The new confidence intervals and sample size when changing confidence level and sample size.

Step-by-step explanation:

a) The new confidence interval would be (0.422, 0.578)

b) The new confidence interval would be (0.439, 0.560)

c) The new confidence interval would be (0.389, 0.611)

d) The new sample size would have to be 480 to make the margin of error half as big in the 98% confidence interval.