x bar (the sample mean)
estimates μ (the population mean)
p hat (the sample proportion)
estimates p (the population proportion)
Sx (the sample st. dev.)
estimates σ (the population st. dev.
statistic
describes characteristics of a sample
parameter
describes characteristics of a population
sampling variability
different random samples of the same size from the same population product different values for a statistic
sampling distribution
distribution of values taken by the statistic in all possible samples of the same size from the same population
unbiased estimator
mean of the sampling distribution is equal to the value of the parameter being estimated
variability
described by the spread of its sampling distribution — inversely proportional to sample size
sampling distribution of the sample proportion p hat
describes the distribution of values taken by the sample proportion p hat in all possible samples of the same size from the same population.
mean of the sampling distribution
standard deviation of the sampling distribution (as long as the 10% condition is satisfied)
sampling distribution is approximately Normal if
the Large Counts condition is satisfied
mean of the sampling distribution of p1-p2
standard deviation of p1-p2 if the 10% condition is met
shape of the sampling distribution of p1-p2 is approximately Normal if
the Large Counts condition is met for BOTH samples
sampling distribution of the sample mean x-bar
distribution of values taken by the sample mean x-bar in all possible samples of the same size from the same population
mean of the sampling distribution of x-bar
standard deviation of the sampling distribution of x-bar as long as the 10% condition is met
central limit theorem
when n is sufficiently large (> or =30), the sampling distribution of the sample mean xis approximately Normal.
mean of the sampling distribution of x1-x2
standard deviation of the sampling distribution of x1-x2 as long as the 20% condition is met
the shape of the sampling distribution of x1-x2 is Normal if
both populations are normal OR if the CLT is satisfied