DIAGRAMS MUST BE DRAWN

Given the standard normal distribution, determine:Prob Z greater than 1.50
Prob Z between1.06 and 1.96
Given the standard normal distribution determine
the Z values that contain 80% in the middle of the curve.

1 answer

You need to draw a normal curve. Label 1.50 and shade in everything from 1.50 to the right under the tail You can look up this value on a calculator or from a Z-table. Be careful because Z-tables may give you only the lower tail.

For 1.06 to 1.96, Again draw the curve and label the two values. (Remember the middle of the curve is "o". Color between these two numbers. Again, this can be done on a calculator, like the TI-83 or use the x-table.

80% in the middle means there is 10% on each side of the middle. If I remember correctly, to have 10% in each tail, the z-value will be -1.645, 1.645. Check a table to be sure.