This question can be found in Chapter 6 Section 63 Problem 2

This question can be found in Chapter 6: Section 6.3. Problem #28: Translate the statement into a confidence interval for p. Approximate the level of confidence. In a survey of 1000 U.S. adults, 19% are concerned that their taxes will be audited by the Internal Revenue Service. The survey\'s margin of error is plus or minus 3%. (Source: Rasmussen Reports)

Solution

CI = p ± Z a/2 Sqrt(p*(1-p)/n)))
x = Mean
n = Sample Size
a = 1 - (Confidence Level/100)
Za/2 = Z-table value
CI = Confidence Interval
p = 0.19
M.E = 0.03
OR C.I = P ± M.E

Lower C.I = P - M.E = 0.19 - 0.03 = 0.16
Upper C.I = P + M.E = 0.19 + 0.03 = 0.22