Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Figure 7-1 (p. 202) The process of constructing the distribution of sample means. A sample is selected, then the sample mean is computed and placed in a frequency distribution. This process is repeated over and over until all the possible random samples are obtained and the complete set of sample means is in the distribution.

Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Figure 7-2 (p. 203) Frequency distribution histogram for a population of 4 scores: 2, 4, 6, 8.

Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Table 7-1 (p. 204) All the possible samples of n = 2 scores that can be obtained from the population presented in Figure 7.2. Notice that the table lists random samples. This requires sampling with replacement, so it is possible to select the same score twice. Also note that samples are listed systematically. The first four examples are all the possible samples that have X = 2 as the first score; the next four samples all have X = 4 as the first score; etc. This way we are sure to have all the possible samples listed, although the samples probably would not be selected in this order.

Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Figure 7-3 (p. 205) The distribution of sample means for n = 2. The distribution shows the 16 sample means from Table 7.1.

Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Table 7-2 (p. 209) The relationship between standard error and sample size.

Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Figure 7-4 (p. 210) The distribution of sample means for n = 25. Samples were selected from a normal population with µ = 500 and σ = 100.

Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Figure 7-5 (p. 212) The middle 80% of the distribution of sample means for n = 25. Samples were selected from a normal population with µ = 500 and σ = 100.

Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Figure 7-6 (p. 214) An example of a typical distribution of sample means. Each of the small boxes represents the mean obtained for one sample.

Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Figure 7-7 (p.215) The distribution of sample means for random samples of size (a) n = 1, (b) n = 4, and (c) n = 100 obtained from a normal population with µ = 80 and σ = 20. Notice that the size of the standard error decreases as the sample size increases.

Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Table 7-3 (p. 216) The mean self-consciousness scores for participants who were working in front of a video camera and those who were not (controls).

Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Figure 7-8 (p. 217) The mean (±SE) score for treatment groups A and B.

Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Figure 7-9 (p. 217) The mean (±SE) number of mistakes made for groups A and B on each trial.

Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Figure 7-10 (p. 219) The structure of the research study described in Example 7.5. The purpose of the study is to determine whether or not the treatment (a growth hormone) has an effect on weight for rats.

Statistics for the Behavioral Sciences, Sixth Edition by Frederick J. Gravetter and Larry B. Wallnau Copyright © 2004 by Wadsworth Publishing, a division of Thomson Learning. All rights reserved. Figure 7-11 (p. 220) The distribution of sample means for samples of n = 25 untreated rats (from Example 7.5).