Hypothesis Testing for Proportions Example 3: Records indicate that 70% of vehicles undergoing emissions tests pass on the first attempt. A random sample of 200 vehicles yields 124 initial passes. Does this suggest that the P= 124 true proportion is not as claimed? Test at a = 0.05. E 200 a) What is the parameter of interest? p= population proportion of vehicles that pass emission test on the first attempt b) State the null and alternative hypothesis. Ho: P : 0.70 HA : P $ 0. 70 c) What is the test statistic? P - po 124 Zobs = - 0. 70 200 0.31- 0.70 SD (P ) 0.76 (1-0.70) = - 2. 469 - - 2.47 0.70(1-0.70) d) What is the p-value? Provide a sketch of the relevant distribution and shade the p-value. 200