Data sets consist of measurements collected over time at regular intervals so that we can learn about change over time

A time-series plot can be constructed by thinking of the data set as a Trivariate data set

are presented in the form of a frequency distribution table.

Ungrouped data: data that gives information on each member of the population or sample individually.

Mean for population data:

mean =

the value of the sample mean 𝑥 varies from sample to sample

Sometimes a data set may contain a few very small or a few very large values. Such values are called

The mean is always the best measure of central tendency because it is heavily influenced by outliers.

The ......... is the value of the middle term in a data set that has been ranked in increasing order

sample median : The single middle value if 𝑛 is ........

median =

The mode is the value that occurs with the highest frequency in a data set.

One advantage of the mode is that it can be calculated

The .............. is a better measure when a data set includes outliers.

The mean is the most-used measure of central tendency, followed by the median

the mean, median, and mode are identical, and they lie at the center of the distribution.

The measures of central tendency, such as the mean, median, and mode, donot reveal the whole picture of the distribution of a data set