36220 Engineering Statistics and Quality Control
Spring 2004 Midterm #1 March 3, 2004
Name: Lab Section:
You have 50 minutes to complete the exam. You must sit at least one seat apart from any neighbor on EACH side (left, right). You m
Midterm Examination Solutions, Statistics 220, Fall 2005
19 October 2005
1
Binomial vs. Poisson
X is a binomial random variable, n = 10, p = 0.1. Y is a Poisson random variable, = 1. (a) What is E [X]? (1 pt) What is Var (X)? (1 pt) What is the p
Stat 220 Final Exam December 16, 2004 Schafer NAME: ANDREW ID:
Read This First: You have three hours to work on the exam. The other questions require you to work out answers to the questions; be sure to show your work clearly. No credit will be
Solutions: Assignment 10
November 23, 2005
12.4
a.
140 0 20 40 60 80 100 120
x
y
Figure 1: boxplot for 12.4 There are a couple of interesting features. First, we see that both x and y have outliers. 2 each. Also, y looks skewed.
b. The scatterpl
Solutions to Homework #9, 36220
Due 16 November 2005
8.54
We are supposed to test whether "the true average percentage of organic matter in such soil is something other than 3%". So our null hypothesis H0 is that = 3. We need a twosided test, sin
36220 Engineering Stats, Fall 2005 Homework 8 Solutions
Due: November 9, 2005
Exercise 8.4
We consider these two hypothesis tests: H0 : H1 : Test 1 =5 >5 Test 2 =5 <5
A desirable hypothesis test keeps the occurrences of type I error (false positi
Solutions: Assignment 7
November 1, 2005
N.D. 1
a.
X bin(n, p) E[X] = np V (X) = np(1  p) E[^] = E[ p = X 1 ] = E[X] n n
1 [np] = p n Bias = (E[^]  p) = p  p = 0 p
b.
V (^) = V ( p X 1 1 ) = 2 V (X) = 2 (np(1  p) n n n p(1  p) = n
c.
S.E(^)
Solutions to Homework #6, 36220
Due 12 October 2005
NonDevore Problem
The rule for variances which says Var (X + Y ) = Var (X) + Var (Y ) only applies if X and Y are uncorrelated random variables, for instance, if X and Y are independent. But here
36220 Engineering Stats, Fall 2005 Homework 5 Solutions
Due: October 5, 2005
NonDevore Exercise
Let T be an exponential random variable that represents the time until a radioactive atom decays and be the rate of decay. a) We formulate the follow
Solutions to Homework Assignment #3 Statistics 220, Fall 2005
Due September 21, 2005
2.52
Let A1 = "pump #1 fails", and A2 = "pump #2 fails". Because the pumps are identical, we can assume that Pr (A1 ) = Pr (A2 ) = q. The problem requires us to fin
Solutions to Homework Assignment #2 Statistics 220, Fall 2005
Due September 14, 2005
The following formula is true for any two events A and B, and is useful in several problems: P (A B) = P (A) + P (B)  P (A B) It follows from the formula for unio
Solutions to Homework Assignment #1 Statistics 220, Fall 2005
Due September 7, 2005
1.10
a
The stemandleaf plot should look something like this. 59 633588 700234677889 8127 9077 107 11368 What constitutes large or small variation usually de
Midterm I Solutions
Problem 1 Since f is a density function
1 0

f ( x)dx = 1. That is
1 1 0

f ( x)dx = f ( x)dx +

3
0
f ( x)dx + f ( x)dx = (a + bx 2 )dx
x 1 b b = 1 a = 1 0= a + 3 3 3 On the other hand, 1 x2 EX= xf ( x)
Midterm Examination, Statistics 220, Fall 2005
19 October 2005
Name:
You have 50 minutes. You can use your own cheatsheet and your own calculator. Please don't share anything. Show your work. Ask us if you need extra scratchpaper. Exercise 1 E
Homework Assignment Statistics 220, Fall 2005
Homework Assignment #1
Problems from Devore:
1. Problem 1.10
2. Problem 1.36
3. Problem 1.38
4. Problem 1.41
5. Problem 1.42
6. Problem 1.44
7. Problem 1.51
Homework Assignment #2
Due September 14
Show your wo