Question 1185791
Ho: proportion=0.37
Ha: proportion NE 0.37
alpha=0.01 p{reject Ho|Ho true}
test is a z
critical value |z|> 2.576
z=(0.28-0.37)/sqrt(0.37*0.63/100)
=-0.09/0.0483
=-1.86
fail to reject Ho: there is insufficient evidence to reject the null hypothesis at the 1% level.
half-interval is (0.995)z*SE=0.1244
99% Interval is (0.246, 0.494)
Because 0.28 is in the interval, we fail to reject Ho. The percentage could be 0.28 with a true percentage of 0.37 and 100 vehicles sampled.