A random variable X follows a normal distribution with mean 20. (standard deviation 5)
Find probability 14=

Question

A random variable X follows a normal distribution with mean 20. (standard deviation 5)
Find probability 14=<X=<26

amistre64 · Answer

since 14 and 26 are not a multiple of 5 from the mean ... how exact, and what tools do you have, to perform this?

anonymous · Answer

I don't know what you mean that's all what it said on my book

amistre64 · Answer

your book also gives you examples on how to solve it .... you might want to flip back a few pages

anonymous · Answer

its not a book but an sample questions from previous exam and it only tells you the answer and doesn't show you how to do it.So do you know how to do it?

amistre64 · Answer

are you able to use a calculator like a ti83?  or do you have to resort to tables in the book?

anonymous · Answer

yeah im able to use a calculator but I also have a maths table book of all the z scores

amistre64 · Answer

ztables are formatted differently by different authors; each one has their own view of what is simpler to do ... thats the only tricky part about a ztable in a book

if you have a ti83 or similar calculator for stats, you should have a normalCDF function on it somewhere

anonymous · Answer

well Im not sure how accurate they are but the whole of Ireland is using it so..
and I cant find that function on my calculator

amistre64 · Answer

we can use the table, but i need to know what the legend looks like:|dw:1369922689565:dw|