Question

A survey​ asked, "How many tattoos do you currently have on your​ body?" Of the

1247

males​ surveyed,

197

responded that they had at least one tattoo. Of the

1025

females​ surveyed,

138

responded that they had at least one tattoo. Construct a

99​%

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

99​%

confidence interval for

p1 - p2

The lower bound is ____

The upper bound is ____

Answer 1

Refer Standard normal table/Z-table or use excel function "=NORM.S.INV((1-0.005))" to find the critical value of z.