In: Statistics and Probability
An engineer randomly inspected 140 rural bridges in a state and found that 50 had serious problems. What is a 95% confidence interval for the proportion of bridges in the state with serious problems? (Show work)
We have given here,
x=50
n=140
Estimate for sample proportion
Level of significance is =1-0.95=0.05
Z critical value(using Z table)=1.96