AP Stats vocab quiz 1

does a census make sense

a census is ok for small populations but not a good idea if the population is big. it would take too long.

what is a parameter

a numerical summary of population

what is a sample

a subset of a population (smaller piece), often taken to make inferences about the population (the whole thing). we calculate statistics from samples.

what is data

any collected information --generally each little measurement

compare DATA-STATISTIC-PARAMETER using quantitative data

data are individual measures (like age). stats and parameters are summaries. a stat would be "the sample average age is 15." a parameter would be "the average age for the population is 15."

compare DATA-STATISTIC-PARAMETER using categorical data

data are individual measures (like meal preference -- tacos, pasta). stats and parameters are summaries. a stat would be "42% of the sample preferred tacos." a parameter would be "42% of the population preferred tacos."

what are the 2 major branches of stats we will study this year

descriptive and inferential

compare descriptive to inferential

descriptive seeks to tell you about what is in the data at hand, inference reaches out to the world at large.

what is variability

differences. how things differ. there is variability everywhere

what is a census

like a sample of the entire population, you get information from every member of the population

what are inferential stats

making inferences - saying what is going on in the population (whole group) using information from a sample (smaller group)

what are descriptive stats

numbers and pictures that describe the nature of a data set, provide info about data that is present

what is a statistic

numerical summary of a sample

what is the difference between a parameter and a statistic

parameters -- population statistics -- samples

compare population to sample

populations are generally large, and samples are small subsets of these population. we take samples to make inferences about populations. we use statistics to estimate parameters.

what is categorical variable

qualitative variables are like categories: hair color, gender, favorite x-men character etc

what is a quantitative variable

quantitative variables are numeric like: Height, age, number of cars sold, SAT score

what is the difference between quantitative and categorical data

quantitative: numerical measures. data is quantitative if you can find the mean categorical: qualitative. data is categorical if you cannot find the mean.

what is the difference between a sample and census

sample -- small part of the population census -- info from the entire population

what is population

the group you're interested in. sometimes it's big, like "all teenagers in the US" other times it is small, like "all MHS Stats students." you calculate parameters from populations

what is stats (technical definition)

the science of collecting, organizing, summarizing, analyzing, and making inferences from data

what is Joe Nystrom's definition of stats

the study of variability

what are random variables

variables whose values are determined by chance. if you randomly choose a student, his hair color is a random variable as well as his height, weight and whether or not he likes penguins.