Question

Could someone help with a proportion question. I am just having trouble using the normal distribution table.

Answer 1

What's up?

Answer 2

So the question asked to find the proportion between 60 and 100 given the mean is 78 and standard deviation is 12

Answer 3

@IMStuck

Answer 4

I found the z score of both and I have p(-1.5 < x < 1.83)

Answer 5

I'm unsure how to find the z-score that corresponds to that probability

Answer 6

Here's a table to refer to:
http://allianthawk.org/victionary/showdef.php?word=217
\[P(-1.5<Z<1.83)=P(Z<1.83)-P(Z<-1.5)\]
This is a property of continuous random variables. Basically, the proportion in between the same as the difference in the proportions to the left of the end points: