Question

1. Use the sample data and confidence level given below to complete parts​ (a) through​ (c).

A research institute poll asked respondents if they felt vulnerable to identity theft. In the​ poll, n=1094 and x=508 who said​ "yes." Use a 90% confidence level.

a) Find the best point estimate of the population proportion p.

b) Identify the value of the margin of error E

c) Construct the confidence interval.

2. In a study of cell phone use and brain hemispheric​ dominance, an Internet survey was​ e-mailed to 2488 subjects randomly selected from an online group involved with ears. 975

surveys were returned. Construct a 95​% confidence interval for the proportion of returned surveys.

a) Find the best point estimate of the population proportion p.

b) Identify the value of the margin of error E.

c) Construct the confidence interval.

3. A clinical trial tests a method designed to increase the probability of conceiving a girl. In the study 360 babies were​ born, and 306 of them were girls. Use the sample data to construct a 99​% confidence interval estimate of the percentage of girls born. Based on the​ result, does the method appear to be​ effective?

Does the method appear to be​ effective?

4. A genetic experiment with peas resulted in one sample of offspring that consisted of 429 green peas and 156 yellow peas.

a. Construct a 95​% confidence interval to estimate of the percentage of yellow peas.

b. It was expected that​ 25% of the offspring peas would be yellow. Given that the percentage of offspring yellow peas is not​ 25%, do the results contradict​ expectations?