Figure 4-1 (p.104) The statistical model for defining abnormal behavior. The distribution of behavior scores for the entire population is divided into three sections. Those individuals with average scores are defined as normal, and individuals who show extreme deviation from average are defined as abnormal.

Figure 4-2 (p. 105) Population distributions of adult heights and adult weights.

Figure 4-3 (p. 107) Frequency distribution for a population of N = 16 scores. The first quartile is Q1 = 4.5. The third quartile is Q3 = 8.0. The interquartile range is 3.5 points. Note that the third quartile (Q3) divides the two boxes at X = 8 exactly in half, so that a total of 4 boxes are above Q3 and 12 boxes are below it.

Figure 4-4 (p. 114) A frequency distribution histogram for a population of N = 5 scores. The mean for this population is µ = 6. The smallest distance from the mean is 1 point, and the largest distance is 5 points. The standard distance (or standard deviation) should be between 1 and 5 points.

Figure 4-5 (p. 116) The graphic representation of a population with a mean of µ = 40 and a standard deviation of σ = 4.

Figure 4-6 (p. 116) The population of adult heights forms a normal distribution. If you select a sample from this population, you are most likely to obtain individuals who are near average in height. As a result, the scores n the sample will be less variable (spread out) than the scores in the population.

Figure 4-7 (p. 118) The frequency distribution histogram for a sample of n = 7 scores. The sample mean is M = 5. The smallest distance from the mean is 1 point, and the largest distance from the mean is 4 points. The standard distance (standard deviation) should be between 1 and 4 points or about 2.5.

Figure 4-8 (p. 119) A sample of n = 3 scores is selected from a population with a mean of µ = 4.

Table 4.1 (p. 122) The set of all the possible samples for n = 2 selected from the population described in Example 4.8. The mean is computed for each sample, and the variance is computed two different ways: (1) dividing by n, which is incorrect and produces a biased statistic; and (2) dividing by n – 1, which is correct and produces an unbiased statistic.

Table 4.2 (p. 123) The number of aggressive responses to male and female children after viewing cartoons.

Figure 4-9 (p. 125) A sketch of a distribution for a sample with a mean of M = 36 and a standard deviation of s = 4. Notice that the distribution is centered around 36 and that most of the scores are within a distance of 4 points from the mean, although some scores are farther away.

Figure 4-10 (p. 127) Graphs showing the results from two experiments Figure 4-10 (p. 127) Graphs showing the results from two experiments. In Experiment A, the variability within samples is small and it is easy to see the 5-point mean difference between the two samples. In Experiment B, however, the 5-point mean difference between samples is obscured by the large variability within samples.