Question

The standard normal curve shown here is a probability density curve for a continuous random variable. This means that the area underneath the entire curve is 1. What is the area of the shaded region between the two z-scores indicated in the diagram?
A. 0.1131
B. 0.6864
C. 0.1151
D. 0.6958
E. 0.6844

Answer 1

okay

Answer 2

see if jaka knos

Answer 3

Do you have a \(z\) table around?

Answer 4

no i dont siths

Answer 5

@jakashaka123

Answer 6

Now you do: http://allianthawk.org/victionary/showdef.php?word=217

The region in the question is the probability that \(z\) falls between -1.23 and 0.86, or
\[P(-1.23<Z<0.86)\]
A property of continuous random variables' probability distributions is that you can split up a probability like so:
\[P(a<X<b)=P(X<b)-P(X<a)\]
This is possible because (assuming \(X\) is normally distributed) you have

So you have to find \(P(Z<0.86)-P(Z<-1.23)\). Have you ever used a \(z\) table before?