Info

Based on the frequency table data, which color is the favorite?

Example The speeds (in m/s) for a race car during five different time trials are 39,37,44,36, and 44.

To find the mean:

Step 1 Find the sum of the numbers.

Step 2 Divide the sum by the number of items, which is 5. 200 ^ 5 = 40

The mean is 40 m/s. To find the median:

Step 1 Arrange the measures from least to greatest. 36,37,39,44,44

Step 2 Determine the middle measure. 36,37,39,44,44

The median is 39 m/s.

To find the mode:

Step 1 Group the numbers that are the same together. 44,44,36,37,39

Step 2 Determine the number that occurs most in the set.

To find the range:

Step 1 Arrange the measures from largest to smallest. 44,44,39,37,36

Step 2 Determine the largest and smallest measures in the set. 44,44,39,37,36

Step 3 Find the difference between the largest and smallest measures. 44 - 36 = 8

Practice Problem Find the mean, median, mode, and range for the data set 8,4,12,8,11,14,16.

Use Geometry

The branch of mathematics that deals with the measurement, properties, and relationships of points, lines, angles, surfaces, and solids is called geometry.

Perimeter The perimeter (P) is the distance around a geometric figure. To find the perimeter of a rectangle, add the length and width and multiply that sum by two, or 2(l + w). To find perimeters of irregular figures, add the length of the sides.

Example 1 Find the perimeter of a rectangle that is 3 m long and 5 m wide.

Step 1 You know that the perimeter is 2 times the sum of the width and length. P = 2(3 m + 5 m)

Step 2 Find the sum of the width and length. P = 2(8 m)

The perimeter is 16 m.

Example 2 Find the perimeter of a shape with sides measuring 2 cm,5 cm, 6 cm,3 cm.

Step 1 You know that the perimeter is the sum of all the sides.

Step 2 Find the sum of the sides.

The perimeter is 16 cm.

Practice Problem Find the perimeter of a rectangle with a length of 18 m and a width of 7 m.

Practice Problem Find the perimeter of a triangle measuring 1.6 cm by 2.4 cm by 2.4 cm.

Area of a Rectangle The area (A) is the number of square units needed to cover a surface. To find the area of a rectangle, multiply the length times the width, or l x w. When finding area, the units also are multiplied. Area is given in square units.

Example Find the area of a rectangle with a length of 1 cm and a width of 10 cm.

Step 1 You know that the area is the length multiplied by the width. A = (1 cm x 10 cm)

Step 2 Multiply the length by the width.Also multiply the units. A = 10 cm2

The area is 10 cm2.

Practice Problem Find the area of a square whose sides measure 4 m.

Area of a Triangle To find the area of a triangle, use the formula:

The base of a triangle can be any of its sides. The height is the perpendicular distance from a base to the opposite endpoint, or vertex.

Example Find the area of a triangle with a base of 18 m and a height of 7 m.

0 0

Post a comment