The Practice of Statistics 4e - Ch 2 Vocab

Cumulative relative frequency graph

Used to examine location within a distribution. Completed graph shows the accumulating percent of observations

Density curve

A curve that (a) is always on or above the horizontal axis, and (b) has exactly 1 area underneath it.

Mean of a density curve

Balance point

Median of a density curve

Equal areas point

Normal Distribution

Is completely specified by two numbers, mean ? and standard deviation ?.

Normal probability plot

Used to assess normality. If the points lie close to a line, the plot indicates that the data are approximately Normal.

Pth percentile

The value with percent of the observations less than it.

Standard Normal distribution

Has mean 0 and standard deviation 1

Standardized values (z-scores)

Tells how many standard deviations a data point is from mean

The 68-95-99.7 Rule

Also known as the "empirical rule.

Cumulative relative frequency graph

Used to examine location within a distribution. Completed graph shows the accumulating percent of observations

Density curve

A curve that (a) is always on or above the horizontal axis, and (b) has exactly 1 area underneath it.

Mean of a density curve

Balance point

Median of a density curve

Equal areas point

Normal Distribution

Is completely specified by two numbers, mean ? and standard deviation ?.

Normal probability plot

Used to assess normality. If the points lie close to a line, the plot indicates that the data are approximately Normal.

Pth percentile

The value with percent of the observations less than it.

Standard Normal distribution

Has mean 0 and standard deviation 1

Standardized values (z-scores)

Tells how many standard deviations a data point is from mean

The 68-95-99.7 Rule

Also known as the "empirical rule.