ASHWORTH MA260.2.1 Assignment 8_08

Assignment
08

MA260 Statistical Analysis I

Directions: Be sure to save an
electronic copy of your answer before submitting it to Ashworth College for
grading. 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 Challengerflight
was the 25^th 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.

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