Ch 8 & 9 definitions
Ch. 8 definitions
Inferential statistics – using information from a sample to reach conclusions about the population from which it was drawn.
Sampling distribution of the mean – the probability distribution of the sample means for all possible samples of that
particular size.
Standard error of the mean – the standard deviation of the sampling distribution.
Central limit theorem – for large, simple random samples from a population that is not normally distributed, the
sampling distribution of the mean will be approximately normal, with the
mean (mu to x-bar = mu) and the standard error (sigma to x-bar = sigma divided by the
square root of n).
Finite population correction factor – the second term in each formula, used to reduce the standard error according to how
large the sample is compared to the population.
Ch. 9 definitions
Point estimate – a single number that estimates the exact value of the population parameter of interest.
Interval estimate – includes a range of possible values that are likely to include the actual population parameter.
Confidence interval – an interval estimate that is associated with a degree of confidence that id actually includes the pop.
Parameter.
Interval estimate – a range of values within which the actual value of the pop. Parameter may fall.
Interval limits – the lower and upper values of the interval estimate.
Confidence interval – an interval estimate for which there is a specified degree of certainty that the actual value of the pop.
Parameter will fall within the interval.
Confidence co-efficient – for a confidence interval, the proportion of such intervals that would include the pop. parameter if
the process leading to the interval were repeated a great many times.
Confidence level – like the confidence coefficient, this expresses the degree of certainty that an interval will include the actual
value of the pop. parameter, but is stated as a percentage.
Accuracy – the difference between the observed sample statistic and the actual value of the pop. parameter being estimated;
also called the estimation or sampling error.
Degree of freedom – (df = n-1) the number of values that remain free to vary once some information about them is
already known.