Applications of Compound Inequalities
Example 1: You are buying a new computer and find 10 models in a store advertisement. The prices are $890, $750,
$650, $370, $660, $670, $450, $650, $725, and $825.
a) Find the mean of the computer prices.
b) You are willing to pay the mean price with an absolute deviation of at most $100. What is the price range
you are willing to shop within?
c) How many of the computer prices meet your condition?
Example 2: You are getting ready to bake muffins while visiting family in England. You know that you need the oven at
350 degrees Fahrenheit with an absolute deviation of at most 3 degrees Fahrenheit.
a) What is the temperature range possible for baking muffins?
b) You are baking in England where the ovens are all in degrees Celsius. Your cousin tells you that you need to
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convert to Celsius by taking the temperature, subtracting 32 and then multiplying by 9.
c) What is the temperature range in degrees Celsius?
CCSSM: A.REI.1, A.REI.3
Unit 4: Inequalities and Absolute Value
Lesson 4.7 – Compound Inequalities Applications
Example 3: The Mars Exploration Rovers Opportunity and Spirit are robots that were sent to Mars in 2003 in order to
gather geological data about the plant. The temperature at the landing sides of the robots can range from -100 degrees
Celsius to 0 degrees Celsius.
a) Write a compound inequality that describes the possible temperatures in degrees Celsius, C.
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b) Knowing that C = 9 (𝐹 − 32) where F is degrees Fahrenheit, solve the inequality to find the range of
temperatures in Fahrenheit.
c) Identify three possible temperatures in degrees Fahrenheit at the landing site.
CCSSM: A.REI.1, A.REI.3
Unit 4: Inequalities and Absolute Value
Lesson 4.7 – Compound Inequalities Applications