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Chapter 18: A. Basic Statistics and Applications 239
an interval (a, b) is shown by the shaded area under the standard normal curve in
Figure 18.28. This probability is determined by using a standard normal distribution
table (see Appendix D).
Standard Normal Distribution Table
The table of the standard normal distribution in Appendix D lists the probabilities
of the random variable Z for its values between z = 0.00 and z = 3.09. A small
portion of this table is reproduced in Table 18.10. The entries in the body of the
table are the probabilities P(0 Z z), where z is some point in the interval (0,
3.09). These probabilities are also shown by the shaded area under the normal
curve depicted at the top of the table. To read this table we mark the row and the
column corresponding to the value of z to one decimal point and the second decimal
point respectively. Then the entry at the intersection of that row and column
–3 0
3
Figure 18.27
The standard normal density function curve.
–3 a
b
3
Figure 18.28 Probability (a Z b) under the standard normal curve.
Table 18.10 A portion of standard normal distribution table from Appendix D.
Part IV.A.5
Z .00 .01 .02 .03 .04 .05 .06 .07 .08 .09
0.0 .0000 .0040 .0080 .0120 .0160 .0199 .0239 .0279 .0319 .0359
0.1 .0398 .0438 .0478 .0517 .0557 .0596 .0636 .0675 .0714 .0753
. .
. .
. .
1.0 .3413 .3438 .3461 .3485 .3508 .3531 .3554 .3577 .3599 .3621
1.1 .3643 .3665 .3686 .3708 .3729 .3749 .3770 .3790 .3810 .3830
. .
. .
. .
1.9 .4713 .4719 .4726 .4732 .4738 .4744 .4750 .4756 .4761 .4767
2.0 .4772 .4778 .4783 .4788 .3793 .4798 .4803 .3808 .4812 .4817