Probability, given standard normal dist: Prob(Z>1.5), etc

Karen

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Mar 13, 2007
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Answer the following questions about the standard normal distribution, Z:

Prob(Z>1.5)

Prob(Z<1.2)

Prob(-1.5<Z<1.2)

Find Z so that 25% of the area under the A curve is to the left of that Z.

Find Z so that 10% of the area under the Z curve is to the right of that Z.

**I have no idea where to get started on this. Any help would be greatly appreciated. Thanks so much! :)**
 
This first step may be to draw a diagram of the normal curve and plot your Z-scores so you can see exactly what each question is asking. Then you'll be able to use your Standard Normal table to find the percentages (areas under the curve)asked for in each question. Add and subtract areas as necessary to determine the answer to each question.

Try that. If you still need help, show us your work and maybe we can help you along a bit more.
 
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