Thursday

March 5, 2015

March 5, 2015

Posted by **Kassie** on Tuesday, April 6, 2010 at 10:01pm.

PLEASE HELP! THIS IS AN EXAM REVIEW QUESTION!

- Statistics -
**Reiny**, Tuesday, April 6, 2010 at 11:10pmfor z-scores,

z = (x - m)/s

from my charts, a prob of .6915 corresponds to a z-score of .5

so .5 = (10 - m)/s

.5s = 10-m

m = 10 - .5s

and a prob of .8413 corresponds to a z-score of .9998 or 1

1 = (20-m)/s

s= 20-m

m = 20 - s

then 20 - s = 10 - .5s

s = -10/-.5 = 20

m = 0

If I recall variance is the square of the standard deviation.

I checked my answers with

http://davidmlane.com/hyperstat/z_table.html

**Answer this Question**

**Related Questions**

Business statistics - 1(a)Let Y have a binomial distribution with parameters n ...

Statistics - Suppose that the fit to the simple linear regression of Y on X from...

statistics - Suppose that you got a score of X=78 on an English test for which ...

Statistics - In a population, heights of males are normally distributed with u=...

Statistics - M/C - 14. The marks on a statistics test are normally distributed ...

statistics - a simple random sample will be obtained from a normally distributed...

statistics - Suppose the average body temp is 98.6 assume the variable is ...

math - I just need help with this. Write the series in sigma notation. 1/4 + 1/2...

math - I just need help with this. Write the series in sigma notation. 1/4 + 1/2...

further mathematics - The roots of the eqn, x^4 + px^3 + qx^2 + rx + s = 0 where...