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. 0.7881
B. 0.6825
C. 0.8937
D. 0.6375
E. 0.4263

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. 0.7881 
B. 0.6825 
C. 0.8937 
D. 0.6375 
E. 0.4263

anonymous · Answer

http://media.apexlearning.com/Images/200708/29/aca838c7-2cb4-4639-9db7-ee927e2c731d.gif

anonymous · Answer

@graze65 hey graze! could you help me with this one please?

anonymous · Answer

Use a z score table to find the area below .8, and then the area below -1.25. .8 is easy since its positive. To deal with the -1.25, find it by looking for 1.25. then subtract that value from 1. After you get the 2 numbers for .8 and -1.25, subtract them.
0.2119 for .8
0.8944 for -1.25 (1-.1056)
subtract those to get .6825

To make it a lot easier, use a calculator:
2nd VARS, normalcdf, then enter the lower and upper values which is -1.25 and upper: .8.
You should get .682

anonymous · Answer

http://www.utdallas.edu/dept/abp/zscoretable.pdf that is the table I used

anonymous · Answer

@graze65 thank you!