Retail Sales These data give the sales volume (in dollars per square foot) for 37 retail outlets specializing in women’s clothing in 2006 and 2007. Did sales change by a statistically significant...

Retail Sales These data give the sales volume (in dollars per square foot) for 37 retail outlets specializing in women’s clothing in 2006 and 2007. Did sales change by a statistically significant amount from 2006 to 2007?

Based on data collected in 2010, 23 percent of women wanted to buy a Google Android smart phone or tablet. Among men, 33 percent were interested in an Android purchase next. The survey contacted 240 women and 265 men.

(a) Might the comparison between these two samples be confounded with a hidden factor? If so, identify such a factor.

(b) Find the 95% confidence interval for the difference between the proportion of men and the proportion women interested in buying an Android device.

(c) What are the implications of the confidence interval for sales executives at Google?