A one-sided confidence interval for p can be written as p <+E or p >-E where the margin of error E is modified by replacing with . If a teacher wants to report,with 90% confidence, that the fail rate on a test is no more than X%, she must construct the appropriate one-sided confidence interval. Assume that a simple random sample of 68 students results in 8 who fail the test and calculate the value of -E. Which of the following is the correct equation for her to use?
Answer
p < 0.068
p > 0.068
p < 0.168
p < 0.182