Tables for Reference

This appendix includes tables for finding probabilities and/or critical values for the three distributions used in this book: the Z-distribution (standard normal), the t-distribution, and the binomial distribution. I explain how to use each table since they are all a bit different.


The Z-table shows less-than-or-equal-to probabilities for the Z-distribution; that is, math for a given z value. (See Chapter 6 for more on the Z-distribution.) To use this table, do the following:

  1. Determine the z-value for your particular problem.

    The z-value should have one leading digit before the decimal point (positive, negative, or zero) and two digits after the decimal point; for example math, math, or 0.13.

  2. Find the row of the table corresponding to the leading digit and first digit after the decimal point.

    For example, if your z-value is 1.28, look in the “1.2” row; if math, look in the “math” row.

  3. Find the column corresponding to the second digit after the decimal point.

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