# 3-9 Weighted Averages by 9m8BFuO

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```									                    3-9 Weighted Averages

Turn to P. 171. Read the passage at the top of the page. Working

1. How would you find the unweighted average of the two
scores?

2. What is the unweighted average of the two scores?

3. How is the weighted average similar to adding another
score?

4. Did the weighted average help or hurt Kulik’s score? Would
this always be the case?
How are mixture and uniform motion problems solved?

The activator is an example of a weighted average.

Weighted average – the sum of the product of the number of units
and the value per unit divided by the sum of the number of units,
represented by M.

Mixture problems – problems in which two or more parts are
combined into a whole.

Mixture problems are solved using weighted averages.

Set up a table to solve the following problems.

Jeri likes to feed her cat gourmet cat food that costs \$1.75 per
pound. However, food at that price is too expensive so she
combines it with cheaper cat food that costs only \$0.50 per pound.
How many pounds of cheaper food should Jeri buy to go with 5
pounds of gourmet food, if she wants the average price to be \$1.00
per pound?
Wes is mixing peanuts and chocolate pieces. Peanuts sell for
\$4.50 a pound and the chocolate sells for \$6.50 a pound. How
many pounds of chocolate mixes with 5 pounds of peanuts to
obtain a mixture that sells for \$5.25 a pound?

10% grape juice. How much pure grape juice would have to be
added to 5 quarts of the drink to obtain a mixture containing 40%
grape juice?
In Mrs. Smith’s class a test is worth four times as much as
homework. If a student has an average of 85% on tests and 95%
on homework, what is the student’s average?

Mr. Pete’s Market has two kinds of nuts. Pecans sell for \$1.55 per
pound and walnuts sell for \$1.95 per pound. How many pounds of
walnuts must be added to 15 pounds of pecans to make a mixture
that sells for \$1.75 per pound?