AP Statistics Study Guide SolutionsQuestions Solved.

Statistical Significance - correct answer An observed effect too large to attribute plausibly to chance. Non-Response Bias - correct answer Bias introduced to a sample when a large fraction of those sampled fails to respond. P-Value - correct answer found by substituting the x-value in the regression equation; they're the values on the fitted line Empirical Rule - correct answer A statistical rule stating that for a normal distribution, almost all data will fall within three standard deviations of the mean. Lurking Variable - correct answer a variable that is not explicitly part of a model but affects the way the variables in the model appear to be related Null Hypothesis - correct answer The null hypothesis attempts to show that no variation exists between variables, or that a single variable is no different than zero. It is presumed to be true until statistical evidence nullifies it for an alternative hypothesis. Quota Sample - correct answer A sampling method of gathering representative data from a group. As opposed to random sampling, quota sampling requires that representative individuals are chosen out of a specific subgroup. Probability - correct answer Quantifiable likelihood (chance) of the occurrence of an event expressed as odds, or a fraction of 1. Descriptive Statistics - correct answer The branch of statistics that includes numerical, graphical, and tabular methods for organizing and summarizing data Median - correct answer the middle value with half of the data above and half below it Stemplot - correct answer A table in which data values are divided into either a "leaf" or a "stem." In a stem and leaf plot, the stem values appear on the vertical axis and the leaf values are listed on the horizontal axis. Data - correct answer systematically recorded information, whether numbers or labels, together with its context Margin of Error - correct answer Analytical technique that accounts for the number of acceptable errors in an experiment. Normal - correct answer Normal distribution with mean of zero and variance of one. Simple Random Sample (SRS) - correct answer this of sample size n is one in which each set of n elements in the population has an equal chance of selection Sampling Distributon - correct answer A type of distribution that involves the probability distribution of sample statistics based on randomly selected samples. Interpolation - correct answer Estimation of an unknown quantity between two known quantities (historical data), or drawing conclusions about missing information from the available information. Qualitative - correct answer involving distinctions based on qualities Theoretical Probability - correct answer Probability based on comparing the number of possible favorable outcomes to the number of total possible outcomes Block Design - correct answer the random assignment of units to treatments is carried out separately within each block Least Squares Regression Line - correct answer the line that makes the sum of the squares of the vertical distances of the data points from the line as small as possible