1. Math 081 Statistics/Geometry Mean Median, Mode Area & Perimeter Formulas

2. Mean
The mathematical average, the number you get when you add up all the numbers in the sample space and divide the sum by the amount of numbers there are.

3. Median
After the numbers are put in numerical order the median is the middle #.
If two numbers are in the middle you take the mean of those two #’s.

4. Mode
The number that appears the most in the sample space. If more then one number appears the most then they are both the mode.
If all numbers appear the same amount of times we say that ALL #’s are the mode.

5. Find the mean, median, and mode for these two sets of #’s
{2, 4, 4, 7, 9, 10, 11, 15}
{1, 2, 6, 6, 9, 9, 25, 30}

6. Example
Put these numbers in order from least to greatest: {-2, 6, 3, 0, -5, 1, -2, 8}

7. Perimeter
The perimeter of an object is the distance around the objects (Find the sum of all the sides in the figure)

8. Squares and Rectangles
The opposite sides of a rectangle have the same length.
All the sides in a square have the same length.

9. Critical Thinking Example
If the perimeter of the triangle is 31 units, then what is the measure of the missing side?
? = 31
18 + ? = 31
? = 13 units

10. Formulas for Triangles & Rectangles
The Area of a rectangle is equal to the length of the rectangle multiplied by the height. A = lw
The Area of a triangle is equal to
½ the Area of a
Rectangle.
A = ½ lw
Area is always written in square units.

11. Volume of a Rectangular Prism/Cube
The volume of a rectangular prism or cube is equal to the product of the length, width and height. (Volume is always written as cubic units)
V = lwh