# Computing Probability and Deciding Extreme Samples

Please explain how to solve. I have attempted to answer, please let me know if I'm right or wrong. Thank you!

a random sample of n=9 scores is selected from a normal distribution with u= 80 and o=12. what is the probability that the sample mean will be between 76 and 84?

* 0.9974

*0.3830

* 0.2586

* 0.6426 ( is this correct?)

a random sample of n= 16 scores is selected from a normal distribution with u= 500 and o= 200. for this sample which of the following is true?

* p(450<M<550)=0.95

*p(425<M<575)=0.95

*p(402<M<598)= 0.95

*p(490<M<510)=0.95

A sample is selected from a normal population with u= 50 and o= 12. which of the following samples would be considered extreme and unrepresentative for this population?

*M=53 and n=4

*M=53 and n= 16

*M=56 and n=4 ( is this correct?)

*M=56 and n=16

https://brainmass.com/statistics/probability/computing-probability-deciding-extreme-samples-584643

#### Solution Preview

1. P(76<X<84)=P((76-80)/(12/sqrt(9))<Z<(84-80)/(12/sqrt(9)))=P(-1<Z<1)=0.6426 from standard normal table

2. We know that P(-1.96<Z<1.96)=0.95. So we ...

#### Solution Summary

The solution gives detailed steps on computing probability of normally distributed data and also deciding extreme samples.