Automobile mechanics conduct diagnostic tests on 150 new cars of particular make and model, to determine the extend to which they are affected by a recent recall due to faulty catalytic converters....

Automobile mechanics conduct diagnostic tests on 150 new cars of particular make and model, to determine the extend to which they are affected by a recent recall due to faulty catalytic converters. They find that 42 of the new cars tested do have faulty catalytic converters.

a. Calculate the standard error of the sample proportion.

b. What is the margin of error for a 99% confidence based on these sample results?

c. Find the 99% confidence interval for the true proportion of new cars with faulty catalytic converters.

d. Interpret the confidence interval in this context