A study of 420,047 cell phone users found that 139 of them developed cancer of the brain or nervous system. Prior to this study of cell phone​ use, the rate of such cancer was found to be 0.0319​%. A) . Use the sample data to construct a 95% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system   B) Do cell phone users appear to have a rate of cancer of the brain or nervous system that is different from the rate of such cancer among those not using cell​ phones? Why or why​ not?

Compute the probability of successfully completing the task for an engineer having 24 months of experience. Place a 95% confidence interval on your estimate.

A Gallup poll of 1487 adults showed that 43% of the respondents have Facebook pages.  Construct a 95% confidence interval for the proportion of adults who have a Facebook page.

A poll reported that only 1316 out of a total of 1746 adults in a particular region said they had a​ "great deal of​ confidence" or​ "quite a lot of​ confidence" in the military. Assume the conditions for using the CLT are met. Complete part​ (a)  (a) Find a 95​% confidence interval for the proportion that express a great deal of confidence or quite a lot of confidence in the​ military, and interpret this interval. The 95​% confidence interval for the proportion that express a great deal of confidence or quite a lot of confidence in the military is: (  ? ,  ? )