COMM-215-2201-AA Week 4: May 25 – May 31 Quiz 3 (Covers Chapters 5 and 6) -
May 28, 2026 at 16:00 until May 29 at 16:00
Started on Thursday, 28 May 2026, 4:00 PM
State Finished
Completed on Thursday, 28 May 2026, 4:28 PM
Time taken 28 mins 39 secs
Grade 16.00 out of 20.00 (80%)
Question 1 A set of final examination grades in a calculus course was found to be normally
Incorrect distributed with a mean of 69 and a standard deviation of 9. What percentage of
students scored between 60 and 90?
Mark 0.00 out of
1.00
Select one:
65.68%
None of the answers are correct.
83.14%
33.00%
98.68%
The correct answer is: 83.14%
Question 2
An aptitude test has a mean score of 60 and a standard deviation of 10. The population
Correct of scores is normally distributed. What proportion of tests has scores over 90?
Mark 1.00 out of
1.00 Select one:
.9772
.0228
.00135
None of the answers are correct.
.0456
The correct answer is: .00135
, Question 3 The Supplies Company buys calculators from a non-US supplier. The probability of a
Incorrect defective calculator is 10 percent. If 150 calculators are selected at random, what is the
standard deviation of the number of defectives?
Mark 0.00 out of
1.00
Select one:
None of the answers are correct.
3.67
9.00
3.17
3.00
The correct answer is: 3.67
Question 4
When a probability distribution is used to approximate a probability
Correct distribution, we must make a correction.
Mark 1.00 out of
1.00 Select one:
discrete, continuous, continuity
continuous, discrete, continuity
continuous, discrete, finite population
discrete, continuous, finite population
None of the answers are correct.
The correct answer is: continuous, discrete, continuity
Question 5
The J.O. Supplies Company buys calculators from a non-US supplier. The probability of
Correct a defective calculator is 10 percent. If 100 calculators are selected at random, what is
Mark 1.00 out of the expected number of defectives?
1.00
Select one:
a. 10 E[X] = μx = (.10)(100) = 10
b. 90
c. 95
d. 9
The correct answer is: 10
May 28, 2026 at 16:00 until May 29 at 16:00
Started on Thursday, 28 May 2026, 4:00 PM
State Finished
Completed on Thursday, 28 May 2026, 4:28 PM
Time taken 28 mins 39 secs
Grade 16.00 out of 20.00 (80%)
Question 1 A set of final examination grades in a calculus course was found to be normally
Incorrect distributed with a mean of 69 and a standard deviation of 9. What percentage of
students scored between 60 and 90?
Mark 0.00 out of
1.00
Select one:
65.68%
None of the answers are correct.
83.14%
33.00%
98.68%
The correct answer is: 83.14%
Question 2
An aptitude test has a mean score of 60 and a standard deviation of 10. The population
Correct of scores is normally distributed. What proportion of tests has scores over 90?
Mark 1.00 out of
1.00 Select one:
.9772
.0228
.00135
None of the answers are correct.
.0456
The correct answer is: .00135
, Question 3 The Supplies Company buys calculators from a non-US supplier. The probability of a
Incorrect defective calculator is 10 percent. If 150 calculators are selected at random, what is the
standard deviation of the number of defectives?
Mark 0.00 out of
1.00
Select one:
None of the answers are correct.
3.67
9.00
3.17
3.00
The correct answer is: 3.67
Question 4
When a probability distribution is used to approximate a probability
Correct distribution, we must make a correction.
Mark 1.00 out of
1.00 Select one:
discrete, continuous, continuity
continuous, discrete, continuity
continuous, discrete, finite population
discrete, continuous, finite population
None of the answers are correct.
The correct answer is: continuous, discrete, continuity
Question 5
The J.O. Supplies Company buys calculators from a non-US supplier. The probability of
Correct a defective calculator is 10 percent. If 100 calculators are selected at random, what is
Mark 1.00 out of the expected number of defectives?
1.00
Select one:
a. 10 E[X] = μx = (.10)(100) = 10
b. 90
c. 95
d. 9
The correct answer is: 10
