Question

In a study of cell phone use and brain hemispheric dominance, an Internet survey was e-mailed to 2457 subjects randomly selected from an online group involved with ears. 935 surveys were returned. Construct a 95% confidence interval for the proportion of returned surveys.

Find the best point estimate of the population proportion p.

Identify the value of the margin of error E.

Construct the confidence intreval.

Answer 1

(0.1886,0.5724)

Explanation:

Given that in a study of cell phone use and brain hemispheric dominance, an Internet survey was e-mailed to 2457 subjects randomly selected from an online group involved with ears. 935 surveys were returned.

Sample proportion of returned surveys =
`(935)/(2457) =0.3805`

Sample size n =2457

q =
`1-0.3805 = 0.6195`

Std error of proportion =
`\sqrt{(pq)/(n) } =0.00979`

a) the best point estimate of the population proportion p.=0.3805

b) Margin of error = 1.96* std error =
`0.1919`

c) Confidence interval =
`(0.3805-0.1919, 0.3805+0.1919)\\= (0.1886,0.5724)`