Some Formulas Sample mean: x = x n (x - x)2 n-1 Sample standard deviation s = x Population mean: = N Population variance: 2 = (x - x)2 N =
( x2 - x)2 N ( x2 - x)2 n
Sample variance: s2 =
=
n-1
s2
N
Po
Math 251, Test 2, 6 November 2007 Name: Hints and Answers
Instructions. Complete each of the following eight questions. Please show all appropriate work in your solutions in order to obtain maximum cr
Math 251, Test 3, 30 November 2007 Name: Instructions. Complete each of the following 7 questions. Please show all appropriate work in your solutions in order to obtain maximum credit. You may use a c
Math 251, Test 3, 30 November 2007 Name: Instructions. Complete each of the following 7 questions. Please show all appropriate work in your solutions in order to obtain maximum credit. You may use a c
Random Variables Expected values and standard deviation for a discrete random variable. = = xp(x) x2p(x) - 2
(x - )2p(x) =
(Linear combinations of r.v.'s) Suppose x1 and x2 are indpendent random vari
Central Limit Theorem Exercises A sampling distribution is a probability distribution of a sample statistic based on all possible simple random samples of the same size from the same population. Centr
Review Questions on Chapters 13 For further practice on questions from Chapters 1 to 3, see Test 1 from Spring 2007, Test 1 from Winter 2007, and Test 1 from Autumn 2003 as available at class website.
Probability: Compound Events Key terms to know: complement, independence, mutually exclusive, conditional probability. Some Rules: P (A) + P (Ac) = 1 so P (Ac) = 1 P (A) P (A and B) = P (A) P (B|A) P
Math 251: Practice Questions from Chapters 13 Hints and Answers I.A. Levels of Data, Types of Samples I.A.1. Categorize the following data according to level: nominal, ordinal, interval, or ratio. (a)