Refer to Problem 13. 

a. Find a 99% confidence interval for the difference, p1 − p2, between the proportions of men and women smartphone owners.

b. Interpret your answer in part (a) in terms of the difference in percentages of men and women smartphone owners

Problem 13

The Pew Internet & American Life The project conducted a survey of smartphone ownership. One aspect of the study involved the gender of smartphone owners. Of 1029 sampled men, 607 owned a smartphone; and of 1223 sampled women,  648 owned a smartphone. At the 1% significance level, do the data provide sufficient evidence to conclude that a difference exists in the percentages of smartphone owners between men and women?