An online survey asked 1,000 adults “ What do you buy from your mobile device?” The results indicated that 61% of the females and 39% of the males answered clothes. (Source: Ebates. com 2014 Mobile Shopping Survey: Nearly Half of Americans Shop from a Mobile Device, available from bit. ly/ 1hi6kyX.) The sample sizes for males and females were not provided. Suppose that both sample sizes were 500 and that 195 out of 500 males and 305 out of 500 females reported they buy clothing from their mobile device.
a. Is there evidence of a difference between males and females in the proportion who said they buy clothing from their mobile device at the 0.01 level of significance?
b. Find the p value in (a) and interpret its meaning.
c. Construct and interpret a 99% confidence interval estimate for the difference between the proportion of males and females who said they buy clothing from their mobile device.
d. What are your answers to (a) through (c) if 270 males said they buy clothing from their mobile device?