Homeworks

Note that doing only the Homework examples is likely insufficient to gain practice and understanding. One learns by doing examples: this is true of all Math, but especially true of Probability. Examples other than the homework are suggested on the schedule. There are also many self-test examples in Ross (the text book).

Note also the information regarding homeworks on the Class home page.

Homework 1; Due 8.30 a.m. Wed October 1
Ross Ch 2: Problems 5, 8,11,19, 23. (note change; see email)

Homework 2; Due 8.30 a.m. Wed October 8
Ross Problems: Ch 1: 9, 15. Ch 2: 28. Ch 3: 1, 9
Ch 1:15: This is how I read the question:
This is a very traditional dance: Ross is a traditional book!!
5 couples will perform a dance, each couple each consisting of a man and a woman.
How many combinations of 5 couples from the dance class are there?
Hint: first choose the participants, then pair them up.

Homework 3; Due 8.30 a.m. Wed October 15
Ross Problems: Ch 3; 11, 20, 26, 32; Ch 4; 1.
Note: this homework covers the same conditional probability material as the midterm. It is not necessary to look at this homework before the midterm -- you have many other examples to look at. However, for those who wish, the first two (Nos 11, 20) are good midterm review.

Homework 4; Due 8.30 a.m. Wed October 22
Ross Problems: Ch 3; 38, 66. Ch 4; 7-8 (a) and (c) only, 42. Ch 5; 4.
Note 1: In Ch 4, 7-8 parts (a) and (c) counts as one total hwk problem.
Note 2: In Ch 5, The cumulative distribution function is the probability that random variable X takes values less than or equal to x (a function of the possible values x).

Homework 5; Due 8.30 a.m. Wed October 29
Ross Problems: Ch 3; 50, 73. Ch 4; 52. Ch 5; 13, 34
Note: In Ch 4, 52: The Poisson distribution is the best model for the number of events, when there are a large number of opportunities for the event, but the probability on any occasion is very small. Here, there are many thousands of flights, and the probability each one will crash is very small. The parameter of the Poisson distribution is equal to the average of the number of events.

Homework 6; Due 8.30 a.m. Wed November 5
Ross Problems: Ch 4; 21, 28, 32, 35, 37.

No homework due on Nov 12: day of midterm-2

Homework 7; Due 8.30 a.m. Wed November 19
Ross Problems: Ch 4: 48, 50, 60, 64; Ch 5: 7.

Homework 8; Due 8.30 a.m. Wed November 26
Ross Problems: Ch 3, 79; Ch 4: 46, 65 (omit (d)), 74,; Ch 5, 20;
Ch 3, 79: the result here "7" or "even" refers to the sum of the two dice.
Hint: First figure the probability the sum is 7, given either 7 or even. Then consider this as a Bernoulli process, where only outcomes 7 or even are counted.
Ch 5, 20; Note the table of Normal probabilities is in Ross on P.222.
Ch. 4, 65: I disagree (very slightly) with the answer in the back of the book: My answer is 0.3929.

Homework 9; Due 8.30 a.m. Wed December 3
Ross Problems: Ch 4: 49, 53, 78. Ch 5: 28, 37.