Math 123 Quantitative Reasoning

Math 123
Quantitative Reasoning

Homework 8 – Sec 9
Weighted Averages

1. An “A” is considered 4.0, a “B” is 3.0, a “C” is 2.0, a “D” is 1.0, and an “F” is 0. In your first semester you received the
following grades. Calculate your grade point average. (round to two decimal places)
Course
Credits
Grade
English
3.0
C
Biology
4.0
B
Communications
3.0
A
New Student Seminar
1.0
A

2. Julie the Jeweler has fifteen gold necklaces worth $120 each, nine silver necklaces valued at $90 each, ten plated
necklaces valued at $60 each and thirty beaded necklaces worth $15 each. What is the average value of a necklace
at Julie’s shop? (round to two decimal places)

3. A worker is exposed to 98 dB for five hours and 82 dB for a three hours, giving an eight hour working day. On
average what noise level is this worker exposed to? (round to the nearest whole number)

4. On a quiz worth 5 points, four students earned a 5, seven students earned a 4, six students earned a 3, two students
earned a 2, and one student earned a zero. Find the average score. (round to one decimal place)

Questions 5-6. Sara is researching phones and decides to create a weighted average to determine the ‘best’. She uses
the following weights: 50% battery life, 30% cost, 20% camera to calculate a ‘score’ for each phone. She finds the
following ratings out of 10 for each category on the internet.
Battery
Cost
Camera
iPhone
9
7
8
Samsung
9
7
7
Motorola
8
9
8
5. Calculate the weighted average ‘score’ for each phone. (round to one decimal place)

6. Which phone should Sara choose based on a weighted averages calculated in the previous question?

Math 123
Quantitative Reasoning
Questions 7-9. A student’s final grade in chemistry is determined by the following weights:
Quizzes
5%
Exam 1
20%
Exam 2
20%
Lab Reports
15%
Research Paper 15%
Final Exam
25%
The student received the following grades:
Lab reports:
75
80 70 75 85 69 90 75
Quizzes:
85
60 70 0
75 80 80 80
Exam 1:
80
Exam 2:
70
Research paper: 85
Final exam:
75
7. What is the average lab report grade for this student? (round to three decimal places)

8. What is the average quiz score? (round to two decimal places)

9. What is the final grade for this student? (round to two decimal places)

Homework 8 – Sec 9
Weighted Averages