21.28 Using public libraries. Exercise 21.13 reports a Pew Research Center Libraries 2015 Survey that found that 922 in a random sample of 2004 American adults said that they had visited, in person, a library or bookmobile in the last year. Use Table 21.1 to give a 99% confidence interval for the proportion of all American adults who have done this. How does your interval compare with the 95% confidence interval of Exercise 21.13?