Sample means, 54–55

• calculation of, 54

• explanation of, 54, 224–225

• formula for, 54

• sampling distribution of, 230–235

• symbol for, 55

Sample median

• calculation of, 56–58

• explanation of, 56, 224

Sample point probabilities

• calculation of, 185–187

• explanation of, 119–122

Sample points

• for coin-tossing experiment, 118

• collection of, 121

• for complex experiments, 124–126

• explanation of, 117–119, 168

Sample size, 55

• central limit theorem and, 452

• determining, 458–459

• method to determine, 399–401

• population mean and, 282–284

• population proportion and, 284–286

Sample space, 118–120

Sample standard deviation, 66

Sample variance, 66

Sample variance formula, 66

Sample z-score, 80

Samples

• biased, 17, 18

• explanation of, 6

• random, 12

• representative, 12

Sampling

• cluster, 184

• independent, 369–379, 451–455

• lot acceptance, 220–221

Sampling distributions

• central limit theorem and, 232–233

• explanation of, 225

• method to find, 226–227

• of sample mean, 230–235

• simulation of, 225

• standard deviation of, 231

Sampling error

• explanation of, 283

• sample size to estimate difference between pair of parameters with specified, 399–400

SAS, linear regression on, 509, 520–521, 551–553

Scatterplots

• explanation of, 93

• normal probability plot as, 210

• use of, 93–95, 506

Selection bias, 14, 18

Self-selection, 15

Sign test, 352–355

• application of, 354–355

• conditions required for valid application of, 354

• explanation of, 352

• large-sample sign test for a population mean, 354

Signed rank test. See Wilcoxon (paired difference) signed rank test

Significance, level of, 312

Significance levels, observed

• explanation of, 318–322

• method to find, 455

Skewness, 57, 58

Slope, 503

Small-sample inferences, 334

• conditions for, 376, 391

Small samples

• conditions for inferences, 376, 391

• population mean comparisons and, 374–379

Spearman, Charles E., 556

Spearman’s rank correlation coefficient, 555–557, 559

• conditions required for a valid, 559

• critical values of, 559

• example of, 557–558

• shortcut formula for, 556

Spread, 65. See also Variability

SPSS, linear regression on, 509, 526

Standard deviation

• for binomial random variable, 189

• of discrete random variable, 175–176

• explanation of, 65–66

• interpretation of, 71–74

• sample, 66

• of sampling distribution, 231

• symbols for, 67

• variability and, 71

Standard error of statistic, 371

Standard normal distribution, 197

Standard normal random variable

• explanation of, 197

• method to find, 198–201

Standard normal table

• explanation of, 196–197

• use of, 198–200

• used in reverse, 204

Statistic, standard error of, 371

Statistical inference. See also Inferences; specific topics

• example of, 74–75

• explanation of, 6

• numerical descriptive measures and, 54

Statistical test

• elements of, 309

• p-values and, 318–322

Statistical thinking, 17

Statisticians, 3

Statistics. See also Descriptive statistics; Inferential statistics; specific topics

• applications of, 3–5

• explanation of, 2–3

• fundamental elements of, 5–9

• types of, 3

Stem-and-leaf display, 46

• benefits and drawbacks of, 46

• explanation of, 43–44, 48

Straight-line model

• estimation using, 510–511, 519

• explanation of, 501, 502

• prediction using, 546

Stratified random sampling, 13

Sum of squares for treatments (SST), 423

Sum of squares of error (SSE), 423, 506, 507

• explanation of, 507

Summation notation, 54

Surveys, 12, 15–18

Systematic sampling, 13