CS 4953 Experimentation in Computer Science Exam 1 Comments: Spring 2003

Exam corrections are due on the Tuesday after spring break in class.
Correct the problems you lost credit on (complete solutions, show all of your work) and receive half the points you lost on the exam. Turn these in with a copy of your exam.

The following are brief comments and answers.

1. There may be several causes, most likely a context switch.
2. Two problems: using the same thread ID and passing the pointer to i.
3. .905
4. mean = 7, standard deviation (sigma) = 3.
5. mean = 4.92, median = 4.5, sample standard deviation = 2.71.
   Don't forget to use the formula for the sample standard deviation.
6. Use the t-distribution with 9 degrees of freedom: (2.483,4.917)
7. mean = 5.9423, sample standard deviation = 3.751. interval: (5.207,6.677)
   Don't use the formula for a distribution variance, use the sample variance.
8. Write a formula for z in terms of the given x. The answer is about .258.