Algebra Concepts Section 12 1 Mean Median and

Algebra Concepts Section 12. 1 Mean, Median and Mode

• Measures of central tendency- a number or numbers representing a collection of data.

• There are four different ways to describe a collection of data. • Sometimes one measure of central tendency is a better way to describe the data.

• The “mean” math teacher averaged my grades.

• Mean is frequently used for grades.

• John has the following grades on tests. 77, 67, 90, 54, 98 Find the mean score. Is he passing?

• Median - middle number when data values are written in order (when there is an odd number of data values). - the mean of the two middle ordered numbers when there is an even number of data values.

• The following is a list of the prices for houses that sold in a community last month. $38, 000 $79, 000 $124, 000 $54, 000 $2, 950, 000 Find the median sale price.

• Mode-the data item that occurs most often. • There can be one mode, more than one, or no mode.

• Range-difference between the greatest and least value in the set of data values.

• Outlier-a data value that is much lower or much higher that the other data values. • Data is collected in the number line above. What is the outlier?

{3, 9, 42, 1, 18, 6, 1} Find the mean. Find the median. Find the mode. Find the range. Find the outlier.

• It is not a good idea to use mean to describe a set of numbers when there is an outlier. • Why?

• https: //www. youtube. com/watch? v=A 7 Mx. Gy Ea. N 64