UNIT 8 Section 4 Distributed Practice #1
MEAN * Mean is the average of a set of numbers. To find the mean, or average of a set of data, add the numbers and divide by the number of entrees.
Example 1: Find the mean of this set of data: 1, 2, 3, 2, 5, 7, 3, 4, 2, 1 Sum: = / 10 = 3 THE MEAN OF THIS SET OF DATA IS 3!!
MEDIAN * The median is the middle number when a set of data is arranged from smallest to largest. In the case of two middle numbers, find the average of the two to determine the median. In the case of two middle numbers, find the average of the two to determine the median.
Example 2: Find the median of the set of data: 8, 5, 4, 9, 11, 2, 14 Put in order: 2, 4, 5, 8, 9, 11, 14 The median of the set of data is 8!!
Example 3: Find the median of the set of data: 23, 14, 25, 32, 17, 40 Put them in order: 14, 17, 23, 25, 32, 40 Average the two: = 48 48/2 = 24 The median of the set of data is 24!!
MODE * The mode of a set of data is the number that occurs most frequently.
Example 5: Find the mode of the set of data: 8, 3, 2, 9, 10, 5, 11, 3, 2, 5, 10, 2 The mode of the set of data is 2!!
Some sets of data have no mode and some sets of data have more than one mode. MODE
Box and Whisker Plot A box and whisker plot is a method of representing data. It looks like this: BOXES
Box and Whisker Plot A box and whisker plot is a method of representing data. It looks like this: Whiskers
Box and Whisker Plot In a box and whisker plot, the boxes represent 50% of the data while each whisker represents 25% of the data. The total represented by the entire plot is 100% 25% 50%
Drawing a Box and Whisker Plot To draw a box and whisker plot, you must first find 5 things: 1. Least Value – Lower Extreme 2. Greatest Value – Upper Extreme 3. Quartile 1 –Lower Quartile 4. Quartile 2 5. Quartile 3upper quartile 5. Quartile 3- upper quartile (median of 1 st half) (median) (median of 2 nd half)
Example 1 Draw a box and whisker plot for this data: 4, 7, 15, 27, 9, 14, 12, 22, 9, 11, 18 First, we must put these numbers in order from least to greatest.
Example 1 Draw a box and whisker plot for this data: 4, 7, 9, 9, 11, 12, 14, 15, 18, 22, 27 Now we can find those 5 things that we need.
Example 1 Draw a box and whisker plot for this data: 4, 7, 9, 9, 11, 12, 14, 15, 18, 22, Least Value 2. Greatest Value 3. Quartile 1 4. Quartile 2 5. Quartile 3
Example 1 Draw a box and whisker plot for this data: 4, 7, 9, 9, 11, 12, 14, 15, 18, 22, Least Value Greatest Value Quartile 1 4. Quartile 2 5. Quartile 3
Quartile 2 Let ’ s find Quartile 2 first. It is the median of the entire group of data. What number is in the middle? 4, 7, 9, 9, 11, 12, 14, 15, 18, 22, 27
Example 1 Draw a box and whisker plot for this data: 4, 7, 9, 9, 11, 12, 14, 15, 18, 22, Least Value Greatest Value Quartile 1 4. Quartile Quartile 3
Quartile 1 Let ’ s find Quartile 1 next. It is the median of the 1 st half of data. What number is in the middle? 4, 7, 9, 9, 11, 12, 14, 15, 18, 22, 27 1 st half
Example 1 Draw a box and whisker plot for this data: 4, 7, 9, 9, 11, 12, 14, 15, 18, 22, Least Value Greatest Value Quartile Quartile Quartile 3
Quartile 1 Let ’ s find Quartile 3 next. It is the median of the 2 nd half of data. What number is in the middle? 4, 7, 9, 9, 11, 12, 14, 15, 18, 22, 27 2 nd half
Example 1 Draw a box and whisker plot for this data: 4, 7, 9, 9, 11, 12, 14, 15, 18, 22, Least Value Greatest Value Quartile Quartile Quartile Now we can draw a box and whisker plot for this data.
Draw a number line that is large enough to include the smallest and largest number. Example 1
Place a dot on the smallest number and largest number.
Example 1 Draw a vertical line on each quartile.
Example 1 Draw horizontal lines to make the boxes.
Example 1 Connect the least and greatest value to create the whiskers.
Example 1
Stem and Leaf A stem-and-leaf plot is a table that represents a group of numbers. (data) The leaves represents numbers in the ones place. The stems represents numbers in the tens and hundreds places.
Drawing a Stem and Leaf Plot Draw an ordered stem-and-leaf plot for the following data for the price of tennis shoes. Make sure the graph is properly labeled.
Drawing a Stem and Leaf Plot PRICES OF TENNIS SHOES: 82, 69, 25, 55, 75, 88, 99, 64, 82, 125, 70
Drawing a Stem and Leaf Plot PRICES OF TENNIS SHOES: 82, 69, 25, 55, 75, 88, 99, 64, 82, 125, 70 Our first step is to write the numbers in order from least to greatest.
Drawing a Stem and Leaf Plot Our next step is to draw a table with two columns -- one for stems and one for leaves PRICES OF TENNIS SHOES: 25, 55, 64, 69, 70, 75, 82, 82, 88, 99, 125
Drawing a Stem and Leaf Plot PRICES OF TENNIS SHOES: 25, 55, 64, 69, 70, 75, 82, 82, 88, 99, 125 StemsLeaves Our next step is to fill in the table. Remember the stem represents the numbers in the tens and hundreds places and the leaves represent the numbers in the ones place
Drawing a Stem and Leaf Plot PRICES OF TENNIS SHOES: 25, 55, 64, 69, 70, 75, 82, 82, 88, 99, 125 StemsLeaves 2 5
Drawing a Stem and Leaf Plot PRICES OF TENNIS SHOES: 25, 55, 64, 69, 70, 75, 82, 82, 88, 99, 125 StemsLeaves
Drawing a Stem and Leaf Plot PRICES OF TENNIS SHOES: 25, 55, 64, 69, 70, 75, 82, 82, 88, 99, 125 StemsLeaves
Drawing a Stem and Leaf Plot PRICES OF TENNIS SHOES: 25, 55, 64, 69, 70, 75, 82, 82, 88, 99, 125 StemsLeaves
Drawing a Stem and Leaf Plot PRICES OF TENNIS SHOES: 25, 55, 64, 69, 70, 75, 82, 82, 88, 99, 125 StemsLeaves
Drawing a Stem and Leaf Plot PRICES OF TENNIS SHOES: 25, 55, 64, 69, 70, 75, 82, 82, 88, 99, 125 StemsLeaves
Drawing a Stem and Leaf Plot PRICES OF TENNIS SHOES: 25, 55, 64, 69, 70, 75, 82, 82, 88, 99, 125 StemsLeaves
Drawing a Stem and Leaf Plot PRICES OF TENNIS SHOES: 25, 55, 64, 69, 70, 75, 82, 82, 88, 99, 125 StemsLeaves
WAIT! ! There ’ s a problem with our stem and leaf plot. In a stem and leaf plot, you don ’ t skip numbers in the stems. If there is no leaf for a stem, then you leave it blank. Let ’ s go back to the last example.
PRICES OF TENNIS SHOES: StemsLeaves This is the correct way to draw the stem and leaf plot for our data.