ENSE 627 Quality Management in Systems
Homework Assignment 5
Chapter 4. Analysis of Data
4.5 Assignment Problems ( Page 4-37 ~4-39 )
4.5.3 On the day before his final examination on ENME ABC, John was
reviewing his exam scores during the past hour exams and quizzes. Can you
guess what score John received on the final examination of ENME ABC?
4.5.4 Mr. John Smith is testing the noise level of two types of
sanders. 2- experiments have been performed for each of the tow types of
sanders. The recorded data in terms of DB are listed as follows. Let us
use two approaches fro the comparison.
4.5.5 Ten students were given a standardized achievement test at
the beginning of the school year(February 1, 1995). They were re-tested
last week (February 8, 1995). The following table listed the data of
their scores. Make a fudgement whether the ten students made an
improvement in taking the standardized achievement test after two month
study at school. (two side test and significance level:10%)
4.5.6 In the early 1960s, the average weight of males at the age of
22 was found to be 160 lbs with a standard deviation of 10.5 lbs. To
determine whether on the average weights of males at the age of 22 are
higher today, a graduate student on the College Park campus selects a
random sample of 64 male students( approximately at 22) and records their
weights.
4.5.7 An electrical circuit manufactured by XYZ Company is
supposed to have a current output of 2.5 amps. To confirm this
specification, 11 circuits without coating are selected randomly and
tested. The following data is the record of the current output.
4.5.8 The following data represent the trade deficits
recorded in 1991 and 1992. The unit is in millions. In the data,
you may notice that the trade deficit in January, 1992 was
extremely high because of the Gulf War. The reason for a low trade
deficit in July, 1992 was due to the payment from Japan to share
the cost of the U.S. troops in Kuwait. The Republican Party
claimed that the Bush Administration achieved, at certain degree, a
trade deficit reduction in 1992. The Democratic Party complained
that the Bush Administration worsened the trade deficit in 1992.
What do you think? Provide your evidence to support your viewpoint.
you may select a significance level.
(1) Calculate the mean and standard deviation of the 20 measurements for
each of the two types of sanders and then make a comparison. Based on the
results, interpret the observed difference. Comment on your work? Which
type is better in terms of the noise level?
(2) Divide the 20 measurements of Sander 1 into tow groups. Calculate the
mean and standard deviation of the 10 measurements for each of the tow
groups and then make a comparison between the two groups. Based on the
results, interpret the difference observed in (1). Comment on your work.
Which type is better in terms of the noise level?
(1) Use the hypothesis test outline to set up statistical procedure to
help decide if today's males are heavier on the average than they used to
be (significance level=0.001)
(2) Suppose the random sample yields a mean weights of 165.4 lbs. Based
on the above procedure, what conclusion should be drawn concerning average
weight of males at the age of 22?
(1) Does the data show that the current output meets the
specification?
(2) An engineer has proposed to use coating for increasing the current
output. he took each circuit listed on the left column, coated with
polyester, and re-tested it. The recorded data is listed in the right
column. Do you believe that the coating method is more effective in terms
of keeping the current output at 2.5 amps.