SOLUTION: Please help me understand this question for my exam tomorrow. Find the z-score such that the interval within z standrard deviations of the mean for a normal distribution contains

Question 324820: Please help me understand this question for my exam tomorrow. Find the z-score such that the interval within z standrard deviations of the mean for a normal distribution contains (A)50% of the probability and (B)90% of the probability.
Answer by scott8148(6628) (Show Source): You can put this solution on YOUR website!
the probabilities are symmetric about the mean (which has a z-score of 0)

for 50% , go into the z-score table and find the .25 area (probability)
___ the associated z-score is above AND below the mean , giving a 50% interval

this may be helpful ___ http://www.mathsisfun.com/data/standard-normal-distribution-table.html
RELATED QUESTIONS
I need help with these problems please explain them to me step by step thanks....I have... (answered by stanbon)

Can someone please help me wit this problem, I cannot understand how to read the z-score... (answered by stanbon)

Hi! Please help me solve this question! Thank you so much! In a normal distribution,... (answered by ewatrrr)

Hi! Please help me with this question! In a normal distribution, find the z-score... (answered by ewatrrr)

Here is a question that someone asked you and you have already answered it. I do not... (answered by stanbon)

Find the value of z, such that P[ -z < Z < z ] = 0.5468 Last one I promise,... (answered by stanbon)

1. The graduate selection committee wants to select the top 10% of applicants. On a... (answered by stanbon)

Please help me solve the question... (answered by Fombitz)

z^(4)-z^(2)-2z+2 Please could someone help me with the last part of this question.... (answered by josgarithmetic)