can someone help me find the 8th percentile on a normal distribution with mean -6 and variance 64.

Question

jim_thompson5910 · Answer

You basically want to find k where

P(X < k) = 0.08

So you can use a calculator or an inverse normal table

anonymous · Answer

how would you go about using your calculator to solve this problem?

jim_thompson5910 · Answer

I'm assuming you have a TI 83 or TI 84?

anonymous · Answer

yes

jim_thompson5910 · Answer

which one?

anonymous · Answer

the 84

jim_thompson5910 · Answer

hit second, then hit the vars key

jim_thompson5910 · Answer

scroll to "invNorm" and hit enter

anonymous · Answer

ok

jim_thompson5910 · Answer

now type in 

0.08, -6, 8)

then hit enter

jim_thompson5910 · Answer

The general format is

invNorm(p, mu, sigma)

where p is the probability (or area under the curve), mu is the mean and sigma is the standard deviation

jim_thompson5910 · Answer

here's more info: http://tibasicdev.wikidot.com/invnorm

anonymous · Answer

got it thank you! had no idea you could solve stat probs on a calc like that
thanks again

jim_thompson5910 · Answer

yw, yes it's very cool since your calculator can do a lot