AP STATISTICS Flashcards

14725556216	continuous variable	a quantitative variable that has an infinite number of possible values that are not countable	0
14725583219	discrete variable	a quantitative variable that has either a finite number of possible values or a countable number of possible values	1
14725595101	numeric variable	a variable whose values are numbers - also called quantitative variable	2
14725599842	categorical variable	a variable that can take on one of a limited, and usually fixed number of possible values, assigning each individual or other unit of observation to a particular group or nominal category on the basis of some qualitative property	3
14757364844	stemplot	used to display quantitative data, generally from small data sets - numeric data is separated by a vertical line (left = stem & right = leaf)	4
14757371421	circle graph	a graph of data where the entire circle represents the whole or 100%	5
14757373222	time series graph	a graph that measures time on the x-axis and the variable or variables in which we are interested on the y-axis	6
14757374348	frequency	measure of how often a data value occurs	7
14757376297	dot plot	a graphical device that summarizes data by the number of dots above each data value on the horizontal axis	8
14757377360	segmented bar chart	displays the conditional distribution of a categorical variable within each category of another variable	9
14757385119	histogram	used to display large sets of continuous numeric variables - vertical bars are used to divide the data into class intervals or bins - the horizontal axis displays the variable of interest and the vertical axis displays the frequency of each data in the interval	10
14757392281	ogive	a graph that represents the cumulative frequencies for the classes in a frequency distribution	11
14757393851	bar chart	used for categorical data - a chart with bars whose lengths are proportional to quantities	12
14811646207	joint frequency distribution	counts of the events in the body of the table	13
14811663192	marginal frequency distribution	totals of each row and each column representing a variable (marginal distribution)	14
14811674197	counts	numbers of items in each category (frequency)	15
14811678656	table total	totals amounts that all rows (or columns) add up to	16
14811692152	two-way frequency table	a table that contains the counts (frequency) or data and organizes it by categorical variables	17
14811725703	conditional frequency distribution	the counts (frequency) of each entry of a specific column or row total	18
14811772388	two-way relative frequency for whole table	uses relative frequencies instead of counts (frequency) for the whole table - (each count/table total) = the relative frequency	19
14811843599	relative frequency	percentage or ratio	20
14936225009	Q3	75th percentile	21
14936274591	maximum	the largest value in a distibution	22
14936276673	five-number summary	the values that create a boxplot	23
14936281010	outliers	an observation that is more or less than 1.5(IQR) away from the 1st and 3rd quartile	24
14936291896	variance	the average of the squares of the deviations of the observations from their mean	25
14936294675	median	the middle of the data set	26
14936296095	minimum	smallest value in a distribution	27
14936298119	IQR	the middle 50% of the distribution	28
14936307562	standard devation	the square root of the variance	29
15025353919	symmetric	both sides are the same	30
15025367027	skewed right	when the tail is to the right	31
15025370206	variability	the spread - distance values are arranged from each other	32
15025373714	skewed left	when the tail is to the left	33
15025378886	resistant	does not change - not affected by outliers	34
15025435628	SOCS	shape, outliers, center, spread	35
15025498591	quantitative data	numerical data - histogram	36
15025512391	qualitative data	descriptive data	37
15025515534	categorical data	consists of names, labels, or other nonnumerical values - bar chart	38
15079493722	normal proportions	when you have restated the problem in a standard normal variable of Z	39
15079501804	standard deviation	the positive square root of the variance	40
15079509144	A-table	is a table of areas under the standard normal curve	41
15079516895	density curve	a curve with an area of one, all graphed above the x-axis	42
15079537717	normal curve	a density curve where the mean is equal to the median	43
15249175034	mean symbol		44
15249211349	standard deviation symbol		45
15249222943	predicted value symbol		46
15249242292	coefficient of determination symbol		47
15249263203	scatterplot	relationship between to quantitative variable measured on the same subject or individual	48
15249276911	dependent variable	variable that measures an outcome of a study	49
15249284693	least squares regression line equation		50
15249358993	z-scale equation		51
15249367839	mean equation		52
15249374950	variance equation		53
15249382021	standard deviation equation		54
15249389562	independent variable	explanatory variable that attempts to explain the observed outcomes	55
15249399414	LSRL	least squares regression line	56
15249414421	residual equation		57
15249450250	y-axis/vertical axis	response variable usually graphed on this axis	58
15249456233	intercept equation		59
15249475628	regression line	straight line that describes how the y responds to the changed in the explanatory variable x	60
15249491718	x-axis/horizontal axis	explanatory variable usually graphed on this axis	61
15249499291	slope of least squares regression line equation		62
15291910429	bivariate data	data with two variables or pairs of numerical observations.	63
15292167346	correlation coefficient	measures the direction and strength of the linear relationship between two quantitative variables - range between -1 and 1	64
15292173380	residual	observed value of the response variable (y) vs. value predicted by the regression equation	65
15292180520	coefficient of determination	percent of variation explained by the least squares regression line	66
15292194556	correlation	measure the strength and direction between two quantitative variables	67
15292271221	correlation coefficient equation		68
15352274517	exponential transformation	transforming every coordinate (x,y) in a data set by replacing y with log(y) for each data value	69
15352295769	transformation	transforming bivariate data refers to replacing either the variable x, y, or both with a simple function of the variable	70
15352301500	power transformation	transforming every coordinate (x,y) in a data set by replacing x with log(x) and y with log(y) for each data value	71
15530184948	sample	a subset of the population	72
15530184949	treatment	something we do in a group in order to observe the affect	73
15530190857	population	the entire group of individuals	74
15530194374	experiment	a technique for establishing the causal relationship between variables	75
15530200561	explainatory variable	independent variable - influences/affects response variable	76
15530208127	parameter	numerical summary of a population	77
15530210399	observational studies	researchers carefully and systematically observe and record behavior without interfering with behavior	78
15530216851	surveys	questionnaires and interviews that ask people directly about their experiences, attitudes, or opinions	79
15530223368	simulations	experiments where researchers create the situation to be studied	80
15530228023	randomization	a process of randomly assigning subjects to different treatment groups	81
15530231182	statistic	a numerical measurement describing some characteristic of a sample	82
15530235113	census	attempts to contact every individual in the entire population	83
15530239790	response variable	variable that measures an outcome of a study	84
15625243487	systematic sample	a sample drawn by selecting individuals systematically from a sampling frame	85
15625244501	convenience sample	a form of non-probability sample using respondents who are convenient or readily accessible to the researcher - i.e. employees, friends, or relatives	86
15625246019	simple random sample (SRS)	of size n consists of n individuals from the population chosen in such a way that every set of n individuals has an equal chance to be the sample actually selected	87
15625247426	cluster sample	obtained by selecting all individuals within a randomly selected collection or group of individuals	88
15625249932	stratified random sample	a sample from selected subgroups of the target population in which everyone in those subgroups has an equal chance of being included in the research	89
15625252724	voluntary response	sampling design where individuals can choose on their own whether to participate in the sample	90
15625254661	non-response	occurs when an individual chosen for the sample can't be contacted or refuses to participate	91
15625255933	wording of question	the most important influence on the answers given to a sample survey	92
15625256479	undercoverage	occurs when some groups in the population are left out of the process of choosing the sample	93
15718131242	experimental units	the smallest collection of individuals to which treatments are applied	94
15718134415	replicate	to repeat, to copy, or to duplicate	95
15718134416	factors	the explanatory variables in an experiment	96
15718137192	table of random digits	a long string of the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 with these properties - each entry in the table is equally likely to be any of the 10 digits 0 through 9 - the entries are independent of each other	97
15718144754	control group	group that is not exposed to the treatment	98
15718149173	placebo effect	experimental results caused by expectations alone - any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent	99
15847651678	matched pairs design	assigning subjects to groups in which pairs of subjects are first matched on some characteristic and then individually assigned randomly to groups	100
15847654627	double-blind	an observation whose true purpose is hidden from both the observer and the person being observed	101
15847656606	factor	something that contributes to a result	102
15847656939	single-blind	experiment in which either the subjects or those who interact with them and measure the response variable, but not both, know which treatment a subject received	103
15847657582	blocking	grouping of individuals according to some characteristic - the random allocation is carried out separately within each group to remove variability associated with the blocking variable	104
15847659787	confounding	occurs when two variables are associated in such a way that their effects on a response variable cannot be distinguished from each other	105
15954016734	simple event	event consisting of only one outcome	106
15954018834	inclusive events	events that have one or more outcomes in common	107
15954019530	law of large numbers	principle stating that the larger the number of similar exposure units considered - the more closely the losses reported will equal the underlying probability of loss	108
15954021120	mutually exclusive	events that cannot occur at the same time	109
15954023119	tree diagram	diagram used to show the total number of possible outcomes	110
15954025474	multiplication rule	to determine the probability, we multiply the probability of one event by the probability of another	111
15954026078	dependent events	the outcome of one event affects the outcome of the second event	112
15954028818	sample space	the set of all possible outcomes	113
15954029377	contingency tables	provide a format to display observations that have more than one value associated with them	114
15954030376	independent events	the outcome of one event does not affect the outcome of the second event	115
15954031853	addition rule	the probability that any one of two or more mutually exclusive events will occur is calculated by adding their individual probabilities	116
16063497396	conditional events	two events are conditional if the probability of one event changes depending on the outcome of another event	117
16114864107	standard deviation of a probability distribution	a number that measures how far the outcomes of a statistical experiment are from the mean of the distribution	118
16114866014	expected value	the mean of a probability distribution	119
16114868982	discrete random variable	a random variable that may assume either a finite number of values or an infinite sequence of value	120
16114872268	continuous random variable	a random variable that may assume any numerical value in an interval or collection of interval	121
16250037505	mean	average	122
16250042703	linear transformation	a transformation involving addition, subtraction, multiplication, or division of or by a constant	123
16337989924	geometric probability	events in calculating geometric probability are also independent, however, the trials stop after the first success occurs	124
16338039259	binomial probability	a probability of getting one of two outcomes (like heads or tails) - success and failure	125
16474111025	continuous random variables	can take up any value between two intervals	126
16474116516	empirical rule	gives the approximate % of observations - 1 standard deviation (68%), 2 standard deviations (95%) and 3 standard deviations (99.7%) of the mean	127
16474120153	normal distribution	function that represents the distribution of variables as a symmetrical bell-shaped graph	128
16474123109	z-score	a measure of how many standard deviations you are away from the mean	129
16569821116	sampling distribution	the distribution of values taken by the statistic in all possible samples of the same size from the same population	130
16569821579	unbiased estimator	the estimator is equal to the true value of the parameter	131
16569825639	Sx	the standard deviation	132
16569826128	standard deviation of the population	σ	133
16569826436	sampling variability	the value of a statistic varies in repeated random sampling	134
16569826454	mean of the population	μ	135
16569827088	x-bar	mean of a sample	136
16569829522	p-hat	sample proportion	137
16569831761	p	the population proportion of a characteristic of interest	138
16602086041	CLT	central limit theorem	139
16602089215	standard deviation of the mean		140