It is generally believed that electrical problems affect about 14% of new cars.An automobile mechanic conducts diagnostic test on 128 new cars on the...

1.     It is generally believed that electrical problems affect about 14% of new cars. An automobile mechanic conducts diagnostic test on 128 new cars on the lot. (12 Points)

a)      Where do we expect the sampling distribution to be centered? Explain why.

b)     What is the standard deviation of the sampling distribution? Show your formulas and calculations.

c)      What is the probability that in this group over 18% of the new cars will be found to have electrical problems? 

What is the z-statistic for this sample? Show your work!

d)     Neatly draw or copy the distribution from StatKey:

e)     What is the p-value for this sample? Indicate the p-value on the graph above.