Page 378 - Statistics for Dummies

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Statistics For Dummies, 2nd Edition
histograms (continued)
boxplots, 117–122
variability in, 109–110
cause-and-effect relationship,
x-axis in, 106
determining, 313–314
y-axis in, 106, 114
horizontal bar graphs, 102
conclusions, avoiding jumping to, 316

confidence intervals, 196–197
horizontal boxplots, 116
correlation, 284–286
horoscopes, statistics in, 30
histograms, 106–110
household incomes, comparing, 86–87
predictions, making, 315
hypotheses, 227
hypothesis tests
projecting from sample to population,
alternative hypothesis, 217
314–315
comparing two population averages,
regression line, 290–291
234–236
scatterplot, 281–282
comparing two population proportions,
surveys, 259–260
test statistic, 220
240–242
time charts, 123–124
data, collecting, 217–218
described, 18–19, 60–61, 215–216
two-way tables, 298–308
interquartile range (IQR), 80, 90, 110, 119
null hypothesis, 216–217 interpretation
paired t-test, 236–240
population mean, 228–229 • J •
sample statistics, gathering, 218
setting up, 216–217 jargon, 45–63
standard errors, measuring variability joint distributions
with, 218–219 calculating, 302–303
standard scores, 219 graphing, 304–305
test statistic, 219–220 overview, 302
testing for an average difference, 236–240
testing one population proportion, 232–234 • K •
t-test, 229–232
“know what you don’t know, and then
• I • do something about it” as exam
strategy, 332
“if-then-how” chart as exam strategy, kth percentile
337–339 calculating, 84–85
impact described, 84
of misleading statistics, 42
of surveys, 248–250 • L •
implications of research results, 276
incorrect numbers, looking for, 328–329 labeling everything in problem as exam
independent ethics committees (IECs), strategy, 340–342
253, 272 land development, statistics about, 26
independent variables, 287, 308–311 leading questions, 253

inflection point, 54, 145 level, 262
institutional review boards (IRBs), 253, 272 lies, 41
Internet virus, statistics about, 24
limitations, 190–191
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