Weighted Averages
Is this Average or Weighted Average?
Adding numbers together and dividing by how many numbers were added.
Ex. (34+45+56+67+78)/5
Average
Which size would you see on the box for a new television whose screen measures 36 inches wide by 27 inches high?
45
How many area codes (ABC) would be possible if all three digits could be any value 1-9?
729
The Jelly Belly jar has a radius of 4.8 cm and a height of 11.8 cm.
What is the volume of the cylindrical jar?
Reminder:
Cylinder’s Volume= 3.14*r^2*h
854.1
What is the check digit (d) for the UPC bar code shown below?
3-21721-02314-d
d=8
Is this Average or Weighted Average?
1. Taking the average of each category
2. Multiplying the averages by the category percentage, and then adding to get an overall grade.
Weighted Average
One bunch of seedlees black grapes costs $2. How many bunches can you buy for $20?
10
How many area codes (ABC) would be possible if all three digits could be any value 0-9?
1,000
When staking the largest jelly beans and lying them down next to each other in the Jelly Belly jar, you get a radius of 3cm and a height of 9cm.
What would be a reasonable lower limit for the number of jelly beans in the jar?
Reminder:
Cylinder’s Volume 3.14*r^2*h
100
What is the check digit (d) for the UPC bar code number 5-11320-36217-d?
d=9
Alexis has the following grades in his math class:
Homework grades: 80, 100, 90
Quiz grades: 84, 90, 72
Test grades: 64, 72
What is the average of each category?
Homework Average: 90
Quizzes Average: 82
Test Average: 68
A student originally sketched some art on an 8.5 inch x 11 inch piece of paper.
She wants to resize it to fit an 8 inch x 10 inch frame
The new picture will have the dimensions 8 inces by 'x' inches.
What percent of the original sketch will still be able to be included in the frame?
(Draw it out to help you solve this)
96.6%
A student number system for a county requires that the student number be 5 characters.
The first 4 characters are any single digit number, but no character can repeat and the last character must be a letter. How many unique student numbers are possible?
131,040
When staking the largest jelly beans and lying them down next to each other in the Jelly Belly jar, you get a radius of 6 cm and a height of 12 cm.
What would be a reasonable upper limit for the number of jelly beans in the jar?
Reminder:
Cylinder’s Volume 3.14*r^2*h
10,000
What is the check digit, d, for the UPC bar code number shown below?
0-24679-36163-d
d=7
Jeyson has the following averages in his math class:
Homework Avg.: 80
Quiz Avg.: 84
Test Avg.: 74
Final Exam: 60
If the teacher weights Homework at 20%, Quizzes at 30%, Tests at 40%, and the Final Exam at 10%, what is Jason’s class average?
77
If the aspect ratio in width:height of a chalkboard is 16:7 and the height is 27 in., what is the width of the chalkboard?
61.7 inches
How many phone numbers are possible in the (770) area code if:
For the form ABC-XXXX, A is restricted to numbers 2-9. B, C, and X can be any digit 0-9. Also, the ABC of the phone number cannot be 911.
7,990,000
A bookstore is hosts the stars from the Harry Potter series for an anniversary book signing. The store has 150’ by 100’ of floor space open for fans to wait. The stars have requested having a 6’ by 6’ space around them so they are not overwhelmed with people. The fire marshal has set the requirement that each person should occupy not less than 2.5 ft2. How many fans can be in the building to meet the stars?
5985 fans
What is the check digit, d, for the VISA number shown below?
4328 3103 2635 108d
d=7
Alexis has the following grades in his math class:
Homework grades: 76, 82, 85
Quiz grades: 74, 80, 80
Test Grades: 60, 68
If the teacher weights homework at 10%, Quizzes at 20%, Tests at 60%, what is her current class average? Please be careful with this one the categories don’t sum to 100% because she hasn’t taken her final exam yet.
69
If you have changed the tires on you car, the original diameter is 24.5 inches. to a new diameter of 26 inches, how fast are you actually going if your speedometer is reading 53 mph?
56.2 mph
A bike lock has a 4 digit combination. Each character can be any digit between 1-9. The only restriction is that all 4 characters cannot be the same (e.g. 1111, 2222, 3333... etc.). How many combinations are possible?
9,990
One rule of thumb for estimating crowds is that each person occupies 2.5 square feet. Use this rule to estimate the size of the crowd watching a concert in an area that is 150 feet long and 240 feet wide.
14,400
What is the check digit, d, for the credit card number shown below?
6424 9813 2720 008d
d=1