(Graded A+)
Sample statistic - Answers a numerical value used as a summary measure for a sample i.e. sample mean,
sample variance, sample standard deviation
population parameter - Answers a numercal value used as a summary measure for a population i.e.
population mean, population variance, population standard deviation
point estimator - Answers the sample statistic, such as sample mean, when used to estimate the
corresponding population parameter
mean - Answers a measure of central location computed by summing the data values and dividing by the
number of observations
median - Answers a measure of central location provided by the value in the middle when the data are
arranged in ascending order.
mode - Answers a measure of location, defined as the value that occurs with greatest frequency
percentile - Answers a value such that at least p percent of the observations are less than or equal to
this value and at least (100-p) percent of the observations are greater than or equal to this value. The
50th percentile is the median
Quartiles - Answers The 25th, 50th, and 75th percentiles, referred to as the first quartile, the second
quartile (median), and the third quartile, respectively. The quartiles can be used to divide a data set into
four parts, with each part containing approximately 25% of the data
range - Answers a measure of variability, defined to be the largest value minus the smallest value
interquartile range (IQR) - Answers a measure of variability, defined to be the difference between the
third and first quartile
variance - Answers a measure of variabiltiy based on the squared deviations of the data values about the
mean
standard deviation - Answers a measure of variability computed by taking the positive square root of the
variance
coefficient of variation - Answers a measure of relative variability computed by dividing the standard
deviation by the mean and multiplying by 100
skewness - Answers a measure of the shape of a data distribution. Data skewed to the left result in
negative skewness; a symmetric data distribution results in zero skewness; and data skewed to the right
result in positive skewness