# Thread: find probability using Excel

1. ## find probability using Excel

Hello,

Could someone kindly review solutions and let me know if it's correct? The problems have to be done using Excel functions.

Here are the final solutions.

Here is the formula used for A.

Here is the formula used for B.

Thank you,

2. ## Re: find probability using Excel

Just to clarify, the answer for A is zero, and the answer for B is 1.

3. ## Re: find probability using Excel

Originally Posted by RBB22
Just to clarify, the answer for A is zero, and the answer for B is 1.
If the probability is 0, then the event is impossible.

If the probability is 1, then the event is certain.

Do your results seem correct to you?

4. ## Re: find probability using Excel

You're using the NORM.DIST function incorrectly. The first argument is the value whose cumulative probability you want to determine, which should be either 9.8 (to get the probability that a sample will be undersized) or 10.2 (to get the probability that a sample will not be over-sized). From that you should be able to determine the probability that any one sample is defective. Then the next step is to determine the mean and standard deviation for the expected number of defective parts in a batch of 1000 (you should be familiar with the binomial distribution). And then finally you should be able to determine the probability that 50 or more parts would be defective out of the batch of 1000. Hope this helps.