probability distribution!

a manufacturer reports the number of major defects for each new automobile that it test using

certain quality control rule; suppose the number of such defects for a certain model is a

random variable with mean 0.32 and standard deviation 0.24. among 50 randomly selected cars

of this model, how likely is the sample average number defects exceeds 6?

pls help here, how do i begin to tackle this problem right?

Re: probability distribution!

Quote:

Originally Posted by

**lawochekel** a manufacturer reports the number of major defects for each new automobile that it test using

certain quality control rule; suppose the number of such defects for a certain model is a

random variable with mean 0.32 and standard deviation 0.24. among 50 randomly selected cars

of this model, how likely is the sample average number defects exceeds 6?

pls help here, how do i begin to tackle this problem right?

Sample is large enough to assume a normal distribution, so the new mean is $\displaystyle 50(0.32)$ and the new standard deviation is $\displaystyle \sqrt{50} (0.24)$. Compute the z-score, and find the probability using a z-score table.