Question

A survey​ asked, "How many tattoos do you currently have on your​ body?" Of the 1213 males​ surveyed, 191 responded that they had at least one tattoo. Of the 1046 females​ surveyed, 133 responded that they had at least one tattoo. Construct a 90​% confidence interval to judge whether the proportion of males that have at least one tattoo differs significantly from the proportion of females that have at least one tattoo. Interpret the interval.

Let p1 represent the proportion of males with tattoos and p2 represent the proportion of females with tattoos. Find the 90​% confidence interval for p1−p2.

The lower bound is ? .

The upper bound is ? .

Answer 1

n1 = 1213
n2 = 1046


Lower Limit =
Upper Limit =
90% Confidence interval is ( 0.0061 , 0.0545 )
( 0.0061 < ( P1 - P2 ) < 0.0545 )

Since value 0 does not lie in the interval, hence we can conclude that the proportion of males that have at least one tattoo differs significantly from the proportion of females that have at least one tattoo.