Question

In a study of cell phone use and brain hemispheric dominance, an Internet survey was e-mailed to 2398 subjects randomly selected from an online group involved with ears. 990 surveys were returned. Construct a 90% confidence interval for the proportion of returned surveys

Find the best point estimate of the population proportion p. (Round to three decimal places as needed.)

Answer 1

To construct a 90% confidence interval for the proportion of returned surveys, calculate the sample proportion and margin of error. Then subtract and add the margin of error to the sample proportion.

Step-by-step explanation:

To construct a 90% confidence interval for the proportion of returned surveys, we need to calculate the sample proportion and the margin of error.

The sample proportion is calculated by dividing the number of returned surveys by the total number of surveys sent out. In this case, the sample proportion is 990/2398 = 0.412.

The margin of error is calculated by multiplying the standard error by the appropriate z-score. The standard error is the square root of [(sample proportion * (1 - sample proportion)) / sample size]. We can calculate the z-score for a 90% confidence interval using the standard normal distribution table or a statistical software.

Once we have the sample proportion and the margin of error, we can calculate the confidence interval by subtracting and adding the margin of error to the sample proportion. So, the 90% confidence interval for the proportion of returned surveys is (0.412 - margin of error, 0.412 + margin of error).