First Quartile (Q1)
The median of the Lower Half of a data set.
Interquartile Range
The difference between the third quartile and the first quartile of a data set; represents the range of the middle half of the data.
Third Quartile (Q3)
The median of the Upper Half of a data set.
Mode
The data value or values that occur most often; Data can have one mode, more than one mode, or no mode.
The modes of the data set 3, 4, 4, 7, 7, 9, 12 are 4, and 7 because they occur most often.
Median
For a data set with an odd number of ordered values, the median is the middle value. For a data set with an even number of ordered values, the median is the mean of the two middle values.
The median of the data set 24, 25, 29, 33, 38 is 29 because 29 is t
Measures of Center
A measure that describes the typical value of a data set.
The mean, median, and mode are all measures of center.
Measures of Variation
A measure that describes the distribution of a data set.
The range, interquartile range, and mean absolute deviation are all measures of variation.
Mean Absolute Deviation
An average of how much data values differ from the mean.
The mean of the data set 5, 7, 12, 16, is 10. The sum of the distances between each data value and the mean is 16. So the mean absolute deviation is 16/4 = 4.
Mean
The sum of the data divided by the number of data values.
The mean of the values 7, 4, 8, and 9 is (7 + 4 + 8 + 9)/ 4 = 28/4 = 7.
Quartiles
The quartiles of a data set divide the data into four equal parts.
First Quartile, Q1 = The Median of the Lower Half of the data sets.
Second Quartile, Q2 = The Median
Third Quartile, Q3 = The Median of the Upper Half of the data set.
Statistics
The science of collecting, organizing, analyzing, and interpreting data.
Statistical Question
A question for which you do not expect to get a single answer.
"What is the daily high temperature in August?
Outlier
A data value that is much greater or much less than the other values.
In the data set 23, 42, 33, 117, 36, and 40, the outlier is 117.
Range (of a data set)
The difference between the greatest value and the least value of a data set.
The range of the data set 12, 16, 18, 22, 27, 35 is 35-12 = 23.
First Quartile (Q1)
The median of the Lower Half of a data set.
Interquartile Range
The difference between the third quartile and the first quartile of a data set; represents the range of the middle half of the data.
Third Quartile (Q3)
The median of the Upper Half of a data set.
Mode
The data value or values that occur most often; Data can have one mode, more than one mode, or no mode.
The modes of the data set 3, 4, 4, 7, 7, 9, 12 are 4, and 7 because they occur most often.
Median
For a data set with an odd number of ordered values, the median is the middle value. For a data set with an even number of ordered values, the median is the mean of the two middle values.
The median of the data set 24, 25, 29, 33, 38 is 29 because 29 is t
Measures of Center
A measure that describes the typical value of a data set.
The mean, median, and mode are all measures of center.
Measures of Variation
A measure that describes the distribution of a data set.
The range, interquartile range, and mean absolute deviation are all measures of variation.
Mean Absolute Deviation
An average of how much data values differ from the mean.
The mean of the data set 5, 7, 12, 16, is 10. The sum of the distances between each data value and the mean is 16. So the mean absolute deviation is 16/4 = 4.
Mean
The sum of the data divided by the number of data values.
The mean of the values 7, 4, 8, and 9 is (7 + 4 + 8 + 9)/ 4 = 28/4 = 7.
Quartiles
The quartiles of a data set divide the data into four equal parts.
First Quartile, Q1 = The Median of the Lower Half of the data sets.
Second Quartile, Q2 = The Median
Third Quartile, Q3 = The Median of the Upper Half of the data set.
Statistics
The science of collecting, organizing, analyzing, and interpreting data.
Statistical Question
A question for which you do not expect to get a single answer.
"What is the daily high temperature in August?
Outlier
A data value that is much greater or much less than the other values.
In the data set 23, 42, 33, 117, 36, and 40, the outlier is 117.
Range (of a data set)
The difference between the greatest value and the least value of a data set.
The range of the data set 12, 16, 18, 22, 27, 35 is 35-12 = 23.