Ch 4 QUIZ. The Normal Curve

Which of the following Z score values represents the location closest to the mean?

+ .50

Using Appendix A in your text, what Z values mark the limits of the middle 75.40% of the area or cases under the normal curve?

+/-1.16

For a population with σ=8 what is the Z score that corresponds to a score that is located 12 points above the mean?

+1.5

For a population with σ=5 what is the Z score that corresponds to a score that is located 10 points above the mean?

+2

Which of the following Z scores is the farthest from the mean?

-2.00

Using Appendix A in your text, what percentage of area or cases under the normal curve will be found between the mean and a Z value of -2.20?

.4861

In the normal curve, the value of the mean is:

0

In the normal curve, the value of the standard deviation is:

1

How much area under the normal curve is found beyond the Z values of +/-2.58?

1%

How much area under the normal curve is found beyond the Z values of +/-1.96?

5%

The Z values of +/-1.96 encompass what percentage of area under the normal curve?

95%

The Z values of +/-2.58 encompass what percentage of area under the normal curve?

99%

A Z score is

Both a and b are correct answers : a point along the base line of the normal curve the ratio of the difference between a score and the mean, divided by the standard deviation (o) Formula to find Z score: z= X - mu / o

Use the following set of scores/values to calculate their Z scores, and the percentage for each set of scores above or below the mean in the normal distribution. Mean: 73 67 75 82 87 Score: 87 63 90 84 70 SD: 4 5 6 3 5 Z: Area: Percentage:

Z = (x-mu)/SD use to fill in the rest of the table:

Which of the following Z scores represents the mean?

Z = 0

The normal curve/distribution is:

a symmetrical distribution

The normal curve/distribution is based upon:

an imaginary sample

Which of the following is true? a. Both the normal distribution and a normal distribution are theoretical b. A normal distribution is empirical and the normal distribution is theoretical c. A normal distribution is theoretical and the normal distribution is empirical d. None of these are true

b. A normal distribution is empirical, and THE normal distribution is theoretical

The normal curve/distribution is a(n)

theoretical curve/distribution