Statistics! help...
Let Z be a standard normal random variable. Determine the value of c such that:

Question

Statistics! help...
Let Z be a standard normal random variable. Determine the value of c such that:

anonymous · Answer

P(Z <= c) = 0.7486

anonymous · Answer

Anyone?

zarkon · Answer

http://onlinestatbook.com/analysis_lab/inverse_normal_dist.html

anonymous · Answer

just find z on z-score table where the area shaded is 0.7487.

anonymous · Answer

I got 0.67. Can someone check to see if that's right?

tkhunny · Answer

No.  How did you get that?  Do you have a table or calculator?  Did you use the link provided?

anonymous · Answer

I used this table: https://controls.engin.umich.edu/wiki/images/c/c2/Group_G_Z-Table.xls

tkhunny · Answer

It is traditional to interpolate between the two closest values.  Thus, 0.6704

Many spreadsheets and calculators have a "qnorm()" function for calculating inverse probabilities.  Excel has one that may appear as this: =NORM.INV(0.7487,0,1) and it gives the value 0.670404.  The interpolation was pretty good!

anonymous · Answer

That's good to know.. thank you!!