# Homework, STAT 400-0401, Fall 2003

Note! For every section in the text we cover -- the main part of your homework is to read that section.

Homework is due in class on the day given. You are welcome and encouraged to help each other in solving the problems, but for homework which is turned in, you must write your own solutions. You can examine each other's solutions, but when you write a solution you must write it without copying. Your solution should give a clear indication of how you came to your answer.

Most homework is from our text,

Jay L. Devore, Probability and Statistics for Engineering and the Sciences, 6th edition (Wadsworth, Belmont, CA, 2000).

### Homework Assignment 1 Due Friday Feb. 6

Section 1.2: 17ac
Section 1.3: 33ab, 41, 42
Section 2.1: 3, 6, 9
Section 2.2: 11, 13, 21, 22, 26

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### Homework Assignment 2 Due Friday Feb. 13

Section 2.3: 33, 39, 40,43
Section 2.4: 45, 46, 51, 60, 62, 64
Ch. 2 Supplementary excercises: 98, 103ab

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### Homework Assignment 3 Due Wednesday Feb. 18

Ch. 2 Supplementary excercises: 99, 105
Section 2.5: 72, 75, 78
Section 3.1: 2, 7 Section 3.2: 11, 12a, 13, 14a, 15, 18, 23
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Also: do the following problems from Sec. 3.3 by Friday Feb. 20, but do not hand them in.
(Section 3.3 is part of what will be covered on Midterm 1, Monday Feb. 23.)
Section 3.3: 28, 29, 32, 34, 37, 42, 43a

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### Homework Assignment 4 Due Friday, March 5

Problem A:
Joe will roll a pair of dice until he rolls a 7 (i.e., the numbers on the two dice sum to 7).
Let \$X\$ be the number of times he will roll without getting a 7.
(For example, if on the third roll Joe first rolls 7, then \$X=2\$.)
What is the expected value of \$X\$?
[Hint: Recall 1 + x + x^2 + x^3 + ... = 1/(1-x), if |x|<1. Now take the derivative of both sides.]

Section 3.4: 45, 46, 47, 49, 51, 61, 62
Section 3.5: 64,70
Section 3.6: 76, 77, 79, 81, 83

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### Homework Assignment 5 Due Monday March 15

Section 4.1: 1, 2, 6, 7
Section 4.2: 11, 18, 21, 23
Section 4.3: 26cdj, 27abd, 29b, 30bc, 35a,37,39,51
Also: by Wed. March 17 do the following problems from Sec. 4.4, but do not hand them in. Section 4.4 is part of what will be covered on Midterm 2, Friday March 19. In Section 4.4, we will only cover the exponential distribution.
Section 4.4: 59, 61, 63

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### Homework Assignment 6 Due Monday, April 5

Section 5.1: 3, 4, 10, 12, 13, 15, 17
(Show enough work that I can see the logic behind the numerical answer--especially when the answer is in the back of the book.)
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### Homework Assignment 7 Due Monday, April 12

Section 5.2: 24, 25, 27 (In #27, to compute the appropriate integral involving |X-Y|, split the square into pieces where X-Y is positive or negative.), 35
Section 5.3: 38
Section 5.4: 46, 47, 53 [In #53b, do not assume the hardness of pins has a normal distribution, and justify the approximation.]

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### Homework Assignment 8 Due Monday, April 19

Section 5.5: 59, 64 69
Section 6.1: 1abcd, 9, 13, 14
Section 6.2: 22, 25a
Also: do, but don't hand in, the following: Supplementary Exercises: 31, 32

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### Homework Assignment 9 Due Wednesday, May 5

Section 7.1: 1bc, 2, 3, 4abe, 7, 11
Section 7.2: 12, 13, 15ab,17,19, 25
Section 7.3: 30acef, 32, 37

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### Homework from Chapter 8 (preparation for Exam 4--do not turn in)

Section 8.1: 1-5,7,9
Section 8.2: 15a,19,28
Section 8.3: 37,38