Posted by **caintgetrite** on Thursday, November 4, 2010 at 11:16pm.

for a sample of n = 75, find the probaBILITY OF A SAMPLE MEAN BEING BEIGN GREATER THAN 221 IF U = 220 AND O = 3.9

- math -
**PsyDAG**, Friday, November 5, 2010 at 10:53am
First, please do not use all capitals. Online it is like SHOUTING. Not only is it rude, but it is harder to understand. Thank you.

I assume "U" = mean and "O" = standard deviation.

Z = (mean1 - mean2)/standard error (SE) of difference between means

SEdiff = √(SEmean1^2 + SEmean2^2)

SEm = SD/√(n-1)

Since only one SD is provided, you can use just that to determine SEdiff.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to that Z score.

## Answer this Question

## Related Questions

Math- Statistics - A random sample of size 36 is to be selected from a ...

statistics - The population mean and standard deviation are given. Find the ...

probability and statistics - the population of sat scores forms a normal ...

Statistics - he Oil Price Information Center reports the mean price per gallon ...

statistics - The population of SAT scores forms a normal distribution with a ...

Statistics - A university has 1,000 computers available for students to use. ...

statistics - Find a number 't' such that the probability that the sample mean ...

statistics - for a sample of n = 36, find the probability of a sample mean being...

Biometrics - If these samples were drawn from a population with mean male weight...

Math check - A random sample of size 26 is to be selected from a population that...