In 2010, some researchers with the Pew Internet & American Life project interviewed a random sample of adults about their cell phone usage. One of the questions asked was whether the respondent had ever downloaded an application or €˜€˜app€ to their cell phone. The sample proportion who had, based on 1917 respondents who had cell phones, was pÌ‚ = 0.29.
(a) Describe how you could construct a bootstrap distribution to estimate the standard error of the proportion in this situation.
(b) One such distribution, based on proportions from 5000 bootstrap samples, is shown in Figure 5.20. The standard deviation of these proportions is 0.0102. Use this information to find a 99% confidence interval for the proportion of cell phone users (in 2010) who have downloaded at least one app to their phone.

Figure 5.20

    

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