Lesson Plan - Get It!
Would you know how to find the best deal if you were buying a new MP3 player? Did you know math could help you with that?
Math helps us with a lot of things, like trying to decide which MP3 player to buy at the best price.
Mean, median, mode, and range can be used to help us understand what the information means. These concepts are used in shopping, sports, temperature, and even in calculating your grades.
Before you can interpret data, you need to know how to find the mean, median, mode, and range of the information in a story problem. Take a moment to review each of these concepts:
||Add all of the values and divide by the number of values in the set.
||Arrange the numbers in order from least to greatest. Find the middle number. If there is an even number of values, add the two middle numbers and divide by two. If there is an odd number of values, the median is the middle value.
||Arrange the numbers in order from least to greatest. The mode is the number or numbers that appear the most. If the numbers appear the same amount of times, then there is "no mode."
||Arrange the numbers in order from least to greatest. Find the difference between the highest value and the lower value.
Here is a fun rhyme to help you remember mean, median, mode, and range:
Hey diddle diddle, the median’s the middle,
You add then divide for the mean.
The mode is the one that you see the most,
And the range is the difference between.
Take a look at how to interpret data in a story problem with this example:
You are shopping for a new MP3 player. After looking through the sales ads, you find the following prices:
$85, $90, $100, $105, $77.
Since it is necessary to put our values in order from least to greatest for median, mode, and range, do that first:
$77, $85, $90, $100, $105
- What is the average price of an MP3 player? "Average" refers to the mean. Add up the values and divide by how many values there are. $77 + $85 + $90 + $100 + $105 = $457. There are 5 values, so divide $457 by 5, which is $91.40. The average price of an MP3 player is $91.40.
- What is the price of the MP3 player that is in the middle of the price range? The middle value is the median. Since we have 5 values, which is an odd amount of values, find the number in the middle. Remember to look at the values in order from least to greatest. The median value is $90.
- What is the most common price of an MP3 player? The most common, or number that appears the most, is the mode. Since each value only appears once, there is "no mode."
- What is the range of the MP3 player prices? The range is found by finding the difference between the highest value and the lowest value. So, $105 - $77 = $28. This means there is a $28 difference between the most expensive and the least expensive MP3 player.
Discuss with you parent or teacher:
- If you wanted to find the most common price of an item, would you use mode or median? Explain.
- If there is "no mode," why can't we say the mode is "zero"? Explain your answer.
Now that you have reviewed the meaning of each concept, move to the Got It? section to practice interpreting data in story problems.