Statistics: Mean, Median, and Mode

mode

the number appearing most often in a set. is a measure of central tendency.

5 number descriptive

mean (x̄), median, standard deviation (σx), Q1, Q3

How to Pull Up a Quartiles Graph

*Step 1:* Zoom Standard, with a blank graph. *Step 2:* 2nd y= (Stat Plots) *Step 3:* Turn on Plot1 *Step 4:* Box and Whisker Plot, or the picture after the histogram *Step 5:* Zoom, 9 (This shows outliers in a visual representation.) *Step 6:* Same as 1-5, but with the bars (histogram)

IQR, interquartile range

a measure of variability, based on dividing a data set into quartiles. (Q3-Q1)

median

the middle number of a set of numbers written in numerical order. is a measure of central tendency.

Ways a Quartiles Graph can be Described

Shape (skewed left/right, symmetric), Outliers (Q1 and Q3), Center (mean and median), Spread (min and max)

outlier

a data point that is distinctly separate from the rest of the data. ( IQR*(1.5)=R; - Q1-R= an outlier; - Q3+R= an outlier.)

statistic

a number that describes some characteristic of sample

Histogram

a visual representation of a data set. It does not show outliers.

Box and Whisker Plot

a visual representation of a data set. It shows outliers.

mean

average of numbers in a set. denoted by x̄. is a measure of central tendency.

quartile

divide a rank-ordered data set into four equal parts. (the values that divide each part are called the first, second, and third quartiles; and they are denoted by Q1, Q2, and Q3, respectively.)

standard deviation

the average distance of observations from their mean. denoted by σx.

range

the difference between the largest and smallest values.