Index Index
addition rule
for mutually exclusive events, sum the probabilities Item
alternative hypothesis
what researchers hope to show Item
analysis of variance (ANOVA)
comparing several group means Assemblage
bar graph
graphical display of categorical data with bars for each category Paragraphs
basic regression model
linearity, equal variance, and normality conditions Assemblage
binomial coefficient
counts ways to select k items from n Exercise
binomial random variable
counts successes in independent trials Assemblage
case-control study Item
coefficient of determination (r-squared)
percentage of variability explained by the regression Assemblage
cohort study Item
complement rule
probability of not A equals 1 minus probability of A Item
conditional proportions Assemblage
confidence interval for mean response
plausible values for the mean response in regression Assemblage
confounding variable Assemblage
correlation coefficient
measure of strength of linear relationship Assemblage
cross-classification study Item
discrete random variable
a random variable with countable possible values Assemblage
expected count
count expected in each cell under the null hypothesis Assemblage
expected value
the long-run average value of a random variable Paragraph
experimental study Assemblage
experimental units Assemblage
explanatory variable Assemblage
extrapolation
predicting outside the range of the data Assemblage
F distribution
reference distribution for ANOVA test statistic Assemblage
Fisher’s Exact Test Assemblage
hurricane
a tropical cyclone with maximum sustained winds of 74 mph or higher Item
hypergeometric distribution Paragraph
Hypergeometric random variable Assemblage
influential observation
removal substantially changes correlation or regression equation Assemblage
least squares line
line minimizing sum of squared residuals Assemblage
major hurricane
a tropical cyclone with max sustained winds of 111 mph or higher Item
mean
the average of all numerical values in the data set Paragraphs
mean group difference
statistic comparing several sample proportions Assemblage
median
a value such that at least 50% of the observations in the data set are smaller than that value and at least 50% of the observations in the data set are larger than that value Paragraphs
model utility test
test of whether the population slope is zero Paragraphs
non-sampling errors Assemblage
null distribution
distribution assuming null hypothesis is true Assemblage
null hypothesis
the "by chance alone" explanation Item
observational study Assemblage
odds of success Assemblage
odds ratio Assemblage
One Proportion z-test
calculates standardized statistic using standard normal distribution Assemblage
p-value
probability of results as extreme as observed, assuming null hypothesis Assemblage
practical significance Paragraphs
prediction interval
plausible values for an individual response Assemblage
probability
the long-run proportion of times an event occurs Assemblage
random assignment Assemblage
random process
generates observations according to a random mechanism Assemblage
random variable
maps outcomes of a random process to numerical values Assemblage
randomized, comparative, double-blind experiment Assemblage
regression effect (regression to the mean)
extreme values tend to be followed by less extreme values Paragraph
regression line Assemblage
relative risk Assemblage
residual
difference between observed and predicted value Assemblage
response variable Assemblage
sample space
a list of all possible outcomes of a random process Assemblage
scatterplot
display of two quantitative variables Assemblage
skewed
a distribution with a longer tail on one side Assemblage
standard deviation
the square root of the variance; a measure of spread in the outcomes of a distribution; roughly the average deviation from the mean of the distribution Assemblage
symmetric
a distribution with a mirror image on each side of the center Assemblage
transformation
re-expressing data to better satisfy model conditions Assemblage
treatment Assemblage
tropical storm
a tropical cyclone with maximum sustained winds of 39 to 73 mph Item
two proportion z-test Paragraphs
two-sample z-test Paragraphs
variance
measures variability in values of a random variable Paragraph
