View Full Version : Need Help Asap!! (z-scores)
12-05-2005, 10:04 PM
:eek: 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.:)
12-05-2005, 10:10 PM
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.
To check your answer, go to:
set the shaded area to 0.88, and click the between button.
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