Statistical Analysis Assign 8
Assignment 08
MA260 Statistical Analysis I
Directions: Unless otherwise stated, answer in complete sentences, and be sure to use correct English, spelling, and grammar. Refer to the "Assignment Format" page located on the Course Home page for specific format requirements.
NOTE: Show your work in the problems.
1. A recent article in the Myrtle Beach Sun Times reported that the mean labor cost to repair a color television is $90 with a standard deviation of $22. Monte’s TV Sales and Service completed repairs on two sets this morning. The labor cost for the first was $75 and it was $100 for the second. Compute z values for each and comment on your findings.
2. The mean of a normal distribution is 400 pounds. The standard deviation is 10 pounds.
a. What is the area between 415 pounds and the mean?
b. What is the area between the mean and 395 pounds?
c. What is the probability of selecting a value at random and discovering that it has a value of less than 395 pounds?
3. The monthly sales of mufflers in the Richmond, VA area follow the normal distribution with a mean of 1200 and a standard deviation of 225. The manufacturer would like to establish inventory levels such that there is only a 5% chance of running out of stock. Where should the manufacturer set the inventory levels?
4. Research on new juvenile delinquents revealed that 38% of them committed another crime.
a. What is the probability that of the last 100 new juvenile delinquents put on probation, 30 or more will commit another crime?
b. What is the probability that 40 or fewer of the delinquents will commit another crime?
c. What is the probability that between 30 and 40 of the delinquents will commit another crime?
5. An Air Force study indicates that the probability of a disaster such as the January 28, 1986 explosion of the space shuttle Challenger was 1 in 35. The Challenger flight was the 25th mission.
a. How many disasters would you expect in the first 25 flights?
b. Use the normal approximation to estimate the probability of at least one disaster in 25 missions.
Grading Rubric
Please refer to the rubric below for the grading criteria for this assignment.
CATEGORYExemplarySatisfactoryUnsatisfactoryUnacceptable
15 points11 points7 points3 points
The student sets up both
equations correctly and
provides the correct answer
for each.
The student sets up both
equations correctly and
provides the correct answer
for only one question.
The student sets up both
equations correctly and
provides the correct answer
for neither question.
The student sets up only
one equation correctly and
provides the correct
answer for only one
question.
15 points11 points7 points3 points
The student sets up all
equations correctly and
provides 3 correct answers.
The student sets up 3
equations correctly and
provides 2 or less correct
answers.
The student sets up 2
questions correctly and
provides 1 or less correct
answers.
The student sets up 1
question correctly and
provides 1 or less correct
answers.
15 points11 points7 points0 points
The student sets up the
equation correctly and
provides the correct answer.
The student sets up the
equation correctly and does
not provide the correct
answer.
The student does not set up
the equation correctly and
does not provide the
correct answer.
The student does not
provide the equation or
the answer.
15 points11 points7 points3 points
The student sets up all
equations correctly and
provides 3 correct answers.
The student sets up 3
equations correctly and
provides 2 or less correct
answers.
The student sets up 2
questions correctly and
provides 1 or less correct
answers.
The student sets up 1
question correctly and
provides 1 or less correct
answers.
15 points11 points7 points3 points
The student sets up both
equations correctly and
provides the correct answer
for each.
The student sets up both
equations correctly and
provides the correct answer
for only one question.
The student sets up both
equations correctly and
provides the correct answer
for neither question.
The student sets up only
one equation correctly and
provides the correct
answer for only one
question.
10 points 8 points 5 points 2 points
Student does not make any
errors in grammar or spelling,
especially those that distract
the reader from the content.
Student makes 1-2 errors in
grammar or spelling that
distract the reader from the
content.
Student makes 3-4 errors in
grammar or spelling that
distract the reader from the
content.
Student makes more than
4 errors in grammar or
spelling that distract the
reader from the content.
15 points 12 points 8 points 5 points
The paper is written in
proper APA and
organizational format. All
sources used for quotes and
facts are credible and cited
correctly. Excellent
organization, including a
variety of thoughtful
transitions.
The paper is written in
proper format with only 1-2
errors. All sources used for
quotes and facts are
credible, and most are cited
correctly. Adequate
organization includes a
variety of appropriate
transitions.
The paper is written in
proper format with only 3-5
errors. Most sources used
for quotes and facts are
credible and cited correctly.
Essay is poorly organized,
but may include a few
effective transitions.
The paper is not written in
proper format. Many
sources used for quotes
and facts are less than
credible (suspect) and/or
are not cited correctly.
Essay is disorganized and
does not include effective
transitions.
The student
includes the
equations and
solves Parts a, b,
and c for #4.
The student
includes the
equations and
answers for Parts a
and b for #5.
Format – APA
Format, Citations,
Organization,
Transitions (15
Points)
The student sets up
the equations for #1
and solves them.
Mechanics (10
Points)
The student solves
Parts a, b, and c for
#2.
The student shows
the equation and
the answer for #3.
January 3rd, 2018 
