Question

The standard normal curve shown below models the population distribution of a random variable. What proportion of the values in the population lies between the two z-scores indicated on the diagram?


A. 0.6825
B. 0.6375
C. 0.7881
D. 0.6766
E. 0.4263

Answer 1

@skinny23 @amistre64 @Luis_Rivera @mathslover @ajprincess

Answer 2

ive never done this in math sorry :/

Answer 3

there are a few ways to approach this, the question is what approach are you spose to use?

ztables, ti83 calculator, other programs?

Answer 4

I'm not sure, it's an online class so they just give me the answer and expect me to know the answer. @amistre64

Answer 5

do you have a ti83 by chance? if not we can drum up a ztable from google images

Answer 6

Yes I have one!

Answer 7

yay! hit 2nd, VARS, and select normalCDF

Answer 8

It is a TI-84

Answer 9

same thing

Answer 10

Okay, done!

Answer 11

its the TI-Nspire that requires a doctorial degree in astroengineering to master

Answer 12

now, there are 4 elements of this function: low, high, mean, std

since they give us Zs, the last 2 are not needed

normalCDF(low,high)

Answer 13

Okay! what is my next step? :)

Answer 14

Would i put normalCDF(-1.3,0.75)?

Answer 15

after inputing the low value and high value ... hit enter :/

normalCDF(-1.3, 0.75) ... enter

Answer 16

How would i write the coma in my calculator?

Answer 17

hit the comma key

Answer 18

should be above the 7

Answer 19

Never mind, I got it. I got .317329858

Answer 20

try it again

Answer 21

2nd
Vars
normalCDF(-1.3,.75)
enter

Answer 22

.6765721712?

Answer 23

much better :)

Answer 24

YAY!

Answer 25

so my answer would be D. 0.6766 :D

Answer 26

THANK YOU SO MUCH!!!

Answer 27

a table could have gotten us there as well, it just would have been a little more complicated :)

Answer 28

Thank you so much, you're amazing!!!!