Question

You want to estimate the proportion of students at OSU who have ever used an online dating app. You select a random sample of 140 OSU students and find that 43% have used an online dating app. If you want to construct a 99% confidence interval, what will the margin of error be? Try not to do a lot of rounding along the way until you get to the end of your calculations?

Answer 1

The margin of error for the proportion of students at OSU who have ever used an online dating app in 99% confidence level is 10.8%

Explanation:

margin of error (ME) around the mean can be found using the formula

ME=
`z*\sqrt{(p*(1-p))/(N) }` where

• z is the corresponding statistic in the given confidence level (2.58)

• p the proportion of students at OSU who have ever used an online dating app in the random sample. (0.43)

• N is the sample size (140)

Putting the numbers in the formula we get

ME=
`2.58*\sqrt{(0.43*0.57)/(140) }` ≈ 0,10795 ≈ 10.8%

Then the confidence interval for the proportion of students at OSU who have ever used an online dating app in 99% confidence level would be 43%±10.8%