Calculating Weighted Average: Calculate The Missing Side based on the formula

Examples with solutions for Calculating Weighted Average: Calculate The Missing Side based on the formula

Exercise #1

A teacher loses the final exam results of one of his students. Luckily for him, he had already calculated the student's average grade for this year.

Attendance: 95 (10%)
Assessment: 82 (10%)
Assignments: 100 (20%)
Final exam: ??? (60%)

If the student's average is 92, then what grade did he get on his final exam?

Video Solution

Answer

90.5

Exercise #2

How much does Javier score on the first exam that has a weight of 55%, given that he scores 76 on the second exam and his final average is 84?

Video Solution

Answer

90.55 90.55

Exercise #3

The price of milk varies from one shop to another.

In two of the shops, the price of milk is 4.5,whileinfiveshopsthepriceofmilkis4.5, while in five shops the price of milk is 5.3.

What is the price of milk in the last two shops if the overall average price is $4.6?

Video Solution

Answer

\( \text{3}.65

Exercise #4

Calculate Martha's grade on an assignment that represents 20% if her average is 80.3 80.3 and her other grades are:

74- 30%

92 - 10%

85 - 15%

74 - 25%

Video Solution

Answer

82 82

Exercise #5

Each building on the street has an average of 4.29 4.29 floors.

There are two buildings with 11 floors, 4 buildings with 2 floors, and 5 buildings with 3 floors.

How many buildings have 5 floors?

Video Solution

Answer

3 3 buildings

Exercise #6

How many times does Andrea run a distance of 3 km if she runs 5.92 5.92 km on average and so far she has run a distance of 8 km 7 times?

Video Solution

Answer

5 5 times

Exercise #7

Matt receives the following grades in his math exams:

75 in an exam that counts for 20%.
82 in an exam that counts for 30%.

94 in an exam that counts for 12%.

If Matt's average is 80.52 80.52 , then what grade did he get on his last exam?

Video Solution

Answer

78 78

Exercise #8

An employee at a paint shop creates the color purple using the colors red and blue.

The red paint costs 70perliter,whilethebluepaintcosts70 per liter, while the blue paint costs 95 per liter.

What percentage of blue and red paint are used if the price of the purple paint is $91 per liter?

Video Solution

Answer

blue: 84% red: 16%

Exercise #9

Each bag of marbles contains an average of 9.64 9.64 marbles.

The first bag has 18 marbles, another two have 12 marbles, and the last three have 7 marbles.

How many bags contain 9 marbles?

Video Solution

Answer

8 8 bags

Exercise #10

In each park of a city24.2 24.2 trees are planted on average.

In the first two parks, 19 trees are planted, while in the next three parks 28 are planted.

How many parks planted 24 trees?

Video Solution

Answer

5 5 parks

Exercise #11

Sebastian has 17 dumbbells that weigh on average 5.22 5.22 kg.

3 of the dumbbells weigh 4.5 kg, 4 dumbbells weigh 5.2 kg, and the rest weigh 7.1 kg or 3.8 kg.

How many dumbbells weighing 7.1 kg does Sebastian have?

Video Solution

Answer

5 5