Question

You want to estimate the proportion of students at OSU who use Instagram. You select a random sample of 150 OSU students and find that 47% use Instagram. If you want to construct a 95% confidence interval, what will the margin of error be? As you calculate this, attempt to round along the way to three decimal places as you are engaging in your calculations in order to make the computations easier. Choose the answer option that is closest to your final answer.  

A 4.1%

B 5.0%

C 8.0%

D 7.3%

E 2.4%

Answer 1

Solution

The margin of error is 8%

Explanation

The Margin of Error (MOE) is calculated according to the formula: MOE = 2 * Vp * (1 - p) / vn Where: z = 1.96 for a confidence level (a) of 95%, p = proportion (expressed as a decimal), n = sample size. z = 1.96, p = 0.47, n = 150 MOE = 1.96 * 10.47* (1 -0.47)/ 150 MOE = 0.978 / 12.247 * 100 = 7.987%

The margin of error is 8%