Need Help Asap!! (z-scores)
- Thread starter heylee2005
- Start date
I am trying to figure out how to find the z-scores that separate the middle 88% of the data from the area in the tails of the standard normal distribution. Any help would be greatly appreciated, because I'm not sure where to start. I really do not understand what the question is asking.
Visualize a normal curve with 88% in the middle, and the remaining 12% divided between the two tails - so there is 6% in each tail.
Now, to find the z score, you look up the value that separates the upper 6% from the lower 94% - in other words, what z-score has 94% of the area under the curve below it?
Then, due to the symmetry of the normal curve, just multiply this z-score by -1 to get the other z-score.
Now, to find the z score, you look up the value that separates the upper 6% from the lower 94% - in other words, what z-score has 94% of the area under the curve below it?
Then, due to the symmetry of the normal curve, just multiply this z-score by -1 to get the other z-score.
To check your answer, go to:
http://psych.rice.edu/online_stat/analysis_lab/inverse_normal_dist.html
set the shaded area to 0.88, and click the between button.
http://psych.rice.edu/online_stat/analysis_lab/inverse_normal_dist.html
set the shaded area to 0.88, and click the between button.