Mental arithmetic: work the following exercises in your head. do not calculate with a pencil or paper. do not use a
decimal.
think of the number seven.
now add eight to it.
now add four more.
now subtract nine.
now add three.
your answer is
14
13
12
11

1. why is a frequency distribution useful? it allows researchers to see the "shape" of the data. it tells researchers how often the mean occurs in a set of data. it can visually identify the mean. it ignores outliers. 2. the is defined by its mean and standard deviation alone. normal distribution frequency distribution median distribution marginal distribution 3. approximately % of the data in a given sample falls within three standard deviations of the mean if it is normally distributed. 95 68 34 99 4. a data set is said to be if the mean of the data is greater than the median of the data. normally distributed frequency distributed right-skewed left-skewed