C E E 5 9 7 – R i s k A n a l y s i s a n d M a n a g e m e n t
PRELIM EXAM, Thursday, March 6, 2008, 7:30-9:00 pm, B-14 Hollister.
Open book and open notes.
Covers material that has appeared in homework, including this assignment.
See Web site for special office hours before exam, and additional old exams.
Readings for this homework on statistics with air travel examples this week
"Airline Safety: Some Empirical Findings"
Barnett and Higgins, "Airline Safety: Some Empirical Findings"
Also: www.AirDisaster.Com, www.AirSafe.Com
Homework Assignment for Wed., March 5, 2008.
Solutions will be distributed that day so late homework will not be accepted.
1. Fires in the home are a significant danger. Tests were made on residual flame time
(seconds) for strips of treated children’s nightwear ( “An introduction to some precision and
accuracy measurements problems,
J. of Testing and Eval.,
1982, pp. 132-140). Regulations
require that the average flame time (time for material to begin to burn) should be longer than
9.80 seconds. Individual tests on different samples yielded flame times of:
9.85, 9.93, 9.75, 9.77, 9.67, 9.87, 9.67, 9.94, 9.85, . . . , 9.89.
Sample average 9.8525, sample standard deviation 0.0965, n = 20.
(a) Does this data suggest that the regulation has been met?
(b) Carry out an appropriate t test and report the p-value for this data set.
(1% < p < 2%)
were 9.85 and the true
population standard deviation
were 0.10, what then is the type II error of the test in part (a) with n = 20 if one used an