Download Assignment 1

King Saud University
College of Engineering
Mechanical Engineering Department
IE 331: Statistical Quality Control
Assignment 1
1- Weibul analysis is a way to quickly and easily analyze field data or interval
Test data. The limits of the use of this technique include having a good
estimate for the:
a – MTBF
b-expected life
c-shape parameter
d- average quality of the production lots
2-A major drawback of using histograms in process control is that they:
a-do not readily account for the factor of time
b-are relatively difficult to construct and interpret
c-require many data points
d-require too many intervals
3-The lengths of a certain bushing are normally distributed with mean X  . How
many standard deviation units, symmetrical about X  , will include 80 percent of
the lengths?
(a) 1.04; (b) 0.52; (c) 1.28; (d) 0.84.
4-The sum of the squared deviations of a group of measurements from their mean
divided by the number of measurements equals:
(a) 2; (b) zero; (c) X ; (d) the mean deviation.
.
5- Given a normal distribution with a mean of 50.0 and a standard deviation of
10.0, what is the probability of obtaining a value between 30.0 and 70.0?
a-0.6826.
b-0.7500.
c-0.9546.
d-0.9973.
6-The normal distribution has _______ parameters. The exponential distribution
has __________ parameters. The weibull distribution has ________ parameters.
a- 1
b- 2
c- 3
d- 4
7-Which of the following assumptions is required for the binomial distribution?
a. The population size is at least ten times the sample size.
b. The sample size is relatively large, say greater than 16.
c. The probability of occurrence is small, say, less than 0.1.
d. All of the above.
8-The normal , exponential , and weibull distributions are examples of-----distributions.
abcd-
Discrete.
Order.
Derived
Continuous.
9-The following data consist of 80 potency measurements of the drug streptomycin.
4.1, 5.0, 2.0, 2.6, 4.5, 8.1, 5.7, 2.5, 3.5, 6.3, 5.5, 1.6, 5.9, 9.3, 4.2, 4.9, 5.6, 3.8, 4.4,
7.1, 4.6, 7.4, 3.5, 4.9, 5.1, 4.6, 6.3, 8.3, 6.3, 8.8, 1.0, 5.3, 5.4, 4.4, 2.9, 7.5, 5.7, 5.3,
3.0, 4.2, 5.2, 7.0, 3.7, 6.7, 5.8, 6.9, 2.8, 6.0, 8.2, 6.1, 7.3, 8.2, 6.2, 4.3, 2.2, 5.2, 5.5,
3.5, 7.1, 7.9, 5.6, 5.4, 3.9, 6.8, 8.2, 4.2, 4.2, 5.5, 6.2, 3.5, 3.4, 6.8, 4.7, 4.6, 4.1, 4.7,
5.0, 3.4, 7.1, 5.2
a- Summarize the data in the tabular form
b- Summarize the data in the graphical form
c- Calculate the following three sets of limits: X ±1s, X ± 2s, X ±3s
10-The following data for wire break strength for supplier B:
470, 425, 438, 620, 452, 573, 382, 486, 526, 300, 520, 450, 389, 371, 598.
Prepare a boxplot for this data.