Les. #7 Descriptive Statistics Mean, Median, Mode and Range The Basics of Statistics Mr. K

Did You Know… That you probably use statistics such as mean, median, mode and range almost every day without even realizing it?!?

Today We Will Learn… Measures of Central Tendency And how to use these in everyday life, as well as the classroom!

What Do We Already Know? Sure, the words “Mean, Median, Mode and Range” all sound confusing… But what about the words we already know, like “Average, Middle, Most Frequent, and Difference”? They are all the same ideas!

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Match Average Middle Most Frequent Difference Mode Range Median Mean Directions: Use the clicker to match each word in the left column with the correct statistics term on the right. Match Average Middle Most Frequent Difference Mode Range Median Mean

Question 1 The following table shows the prices of six laptop computer models. Laptop Prices Laptop Model Retail Price PV 8500 $999.99 PV 8200 $899.99 PV 7800 $879.99 PV 7400 $849.99 PV 6900 PV 6800 $749.99 Which statistical measurement does not increase when a new laptop model that retails for $1,399.99 is added to the table? F. Mode G. Mean H. Median J. Range

Question 2 The prices, in dollars, of the cars sold by a used car salesperson one week are shown below. 4300, 5400, 3200, 6200, 5400, 5500, 6400 The price of the next car sold by the salesperson was $14,000. Which measure will have the greatest change when the price of the last car sold is included in the list? A. Mean B. Median C. Mode D. Range

Box-and-Whisker Plots

Step 1 – Order Numbers 1. Order the set of numbers from least to greatest

Step 2 – Find the Median Find the median. The median is the middle number. If the data has two middle numbers, find the mean of the two numbers. What is the median?

Step 3 – Upper & Lower Quartiles Find the lower and upper medians or quartiles. These are the middle numbers on each side of the median. What are they?

Step 4 – Draw a Number Line Now you are ready to construct the actual box & whisker graph. First you will need to draw an ordinary number line that extends far enough in both directions to include all the numbers in your data:

Step 5 – Draw the Parts Locate the main median 12 using a vertical line just above your number line:

Step 5 – Draw the Parts Locate the lower median 8.5 and the upper median 14 with similar vertical lines:

Step 5 – Draw the Parts Next, draw a box using the lower and upper median lines as endpoints:

Step 5 – Draw the Parts Finally, the whiskers extend out to the data's smallest number 5 and largest number 20:

Step 6 - Label the Parts of a Box-and-Whisker Plot Minimum (Lowest Value) Maximum (Highest Value) Median Lower Median (1st Quartile) 4 1 5 Upper Median (3rd Quartile) 3 2 Name the parts of a Box-and-Whisker Plot

Homework RC: Pg. 645 – 647 , 1 – 5, 8 – 13 HC: pg. 645 – 647, 1 – 13