Unformatted text preview: 111413326 Engineering Test Design and Analysis Prerequisite Quiz 5. The lengths of screws produced by a machine are normally distributed with a mean of 3
inches and a standard deviation of .2 inches. Therefore, we know:
”a. that approximately 68 percent of all screws have lengths between 2.8 and 3.2 inches
b. that approximately 95 percent of all screws have lengths between 2.8 and 3.2 inches
c. that just about all screws have lengths between 2.8 and 3.2 inches
d. that approximately 98 percent of all screws have lengths between 2.8 and 3.2 inches
e. None of these 6. The following ten scores were obtained on a 20-point quiz: 4, 5, 8, 9, 11, 13, 15, 18, 18, and
20. The teacher computed the usual descriptive measures of center (central tendency) and variability (dispersion) for these data, and then discovered an error was made. One of the
18's should have been a 16. Which one of the following measures, calculated on the corrected data, would change from the original computation?
a. Mean and standard deviation b. Mean and median c. Range and median (31. Mean and range. 7. Which of the following randomly selected measurements, x, might be considered a potential
outlier (i.e., an unusual measurement) if it was selected from the given population?
a x = 0 from a population with ,2: = 0 and cr = 2 b. x = -5 from apopulation with ,u = 1 and 0' = 4
c. x? 7 fromapopulation with n =3 and 0 =2
d. x = 4 from a population with u = D and 0 =1 f . 8. A student took a chemistry exam where the exam scores were mound-shaped with a mean
score of 90 and a standard deviation of 64. She also took a statistics exam where the scores 1
were mound-shaped, the mean score was 70 and the standard deviation was 16. If the f/ 816 J H student's grades were 102 on the chemistry exam and 77 on the statistics exam, then r H—
a. the student did relatively better on the chemistry exam than on the statistics exam,
compared to the other studeiits in each class.
b. the student did relatively better on the statistics exam than on the chemistry exam,
compared to the other students in the two classes.
:3. the student’s scores on both exams are comparable, when accounting for the scores of the
other students in the two classes.
d. it is impossible to say which of the student's exam scores indicates the better performance. 9. In constructing a scatterplot, it woald not be appropriate to
label the x and y axes label the graph using titles
connect the data points on the graphs with straight lines draw the best ﬁtting line on the graph Page Page 2 of4 ...
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- Winter '08