Unit 6 A Vocabulary Box Plot A plot

Unit 6 A Vocabulary

Box Plot A plot showing the minimum, maximum, first quartile, median, and third quartile of a data set; the middle 50% of the data is indicated by a box. Example:

Dot Plot A frequency plot that shows the number of times a response occurred in a data set, where each data value is represented by a dot. Example:

Histogram A frequency plot that shows the number of times a response or range of responses occurred in a data set. Example:

First Quartile The value that identifies the lower 25% of the data; the median of the lower half of the data set; written as Example:

Third Quartile Value that identifies the upper 25% of the data; the median of the upper half of the data set; 75% of all data is less than this value; written as Example:

Median The middle-most value of a data set; 50% of the data is less than this value, and 50% is greater than it Example:

Mean The average value of a data set, found by summing all values and dividing by the number of data points Example: 5 + 4 + 2 + 6 + 3 = 20 The Mean is 4

Interquartile Range The difference between the third and first quartiles; 50% of the data is contained within this range Example: Subtract Third Quartile ( ) – First Quartile ( ) = IQR

Mean Absolute Deviation (MAD) The average absolute value of the difference between each data point and the mean; found by summing the absolute value of the difference between each data point and the mean, then dividing this sum by the total number of data points Example: Steps: 1. Find the Mean 2. Calculate the absolute value of the difference between each data value and the mean 3. Determine the average of the differences in step 2. This average is the mean absolute deviation

Measures of Center Values that describe expected and repeated data values in a data set; the mean, median, and mode are measures of center Example: Find the Mean and Median for the following data. Hint: (Must order the numbers first before finding the Median) 21543 Mean: Median = 3

Measures of Spread A measure that describes the variance of data values, and identifies the diversity of values in a data set • Example: Examples of Measures of Spread: 1. Range 2. Interquartile Range (IQR) 3. Mean Absolute Deviation (MAD)

Outlier A data value that is much greater than or much less than the rest of the data in a data set Example:

Skewed to the left Data concentrated on the higher values in the data set, which has a tail to the left. Example:

Skewed to the Right Data concentrated on the lower values in the data set, which has a tail to the right. Example:

Symmetric Situation in which data is concentrated toward the middle of the range of data; data values are distributed in the same way above and below the middle of the sample. Example: