Question

The standard normal curve shown below models the population distribution of a random variable. What proportion of the values in the population does not lie between the two z-scores indicated on the diagram?

Answer 1

heres the picture

Answer 2

Ahhh I'm not sure how to do the problem. Sorry hun!!

Answer 3

You'll have to use a calculator, or a table of z-values, to find \[\large P(-1.25<z<0.80) =\]

Answer 4

i have no idea how you got that..

Answer 5

If you use a z-table, you might need to do it like so\[\large P(-1.25<z<0.80) = \]
\[\large P(z<0.80)-P(z<-1.25)\]

Answer 6

The values given on the graph are z-scores. You need to first find the area between those two z-scores, which is what I gave you.

Once you have that, then you subtract that area from 1, to find the area outside the shaded region.

Answer 7

So, the thing you need to actually find is this \[\large 1-P(-1.25<z<0.80) =\]

Answer 8

that doesnt make sense to me

Answer 9

from my tables of statistics, I get these results:
\[\Large \begin{gathered}
P > 0.8 = 0.2119 \hfill \\
\hfill \\
P < - 1.25 = 0.1056 \hfill \\
\end{gathered} \]

Answer 10

so the requested probability, is:
\(0.2119+0.1056=...?\)

Answer 11

0.3175?

Answer 12

that's right!

Answer 13

@Michele_Laino if nothing I wrote made sense to her, then nothing you gave her will help her understand.