Researchers conducted a study of smartphone use among adults. A cell phone company claimed that iPhone smartphones are more popular with whites (non-Hispanic) than with African Americans. The results of the survey indicate that of the 232 African American cell phone owners randomly sampled, 5% have an iPhone. Of the 1,343 white cell phone owners randomly sampled, 10% own an iPhone. Find a 95% confidence interval for the difference in proportions between white and African American smartphone users.
FIND YOUR POINT ESTIMATOR
p1		p2		p1- p2
CHOOSE YOUR Z VALUE
Z =
CALCULATE SIGMA	a			b
(p1 (1-p1))/n1		(p2(1-p2))/n2		sqrt(a+b)
CALCULATE MARGIN OF ERROR
ME =
CALCULATE CONFIDIENCE INTERVAL
Point Estimator Marigin of Error
Interval
Algebraic