Alvin Poyser PAM 210 Prelim 2 Chapter 2: Association- two variables are assoc. if some values of one variable tend to occur more often with some values of the other variable. Response variable- measures an outcome of a study. Explanatory variable- ex

PAM 2100 Spring 2009 Problem Set #7 Answer Key Total points: 10
#1) from the textbook: 7.38 Use df=1000. Round your final answer to four decimal places. (2 points) (The actual degree of freedom of this problem is 1406-1=1405. But since we do not hav

Question 1
1 points Save
A college decides to admit 1300 students. Past experience shows that 80% of the students admitted will accept. Assuming that students make their decisions independently, the number who accept has the B(1300, 0.8) distribution. Rou

PAM 2100 FALL 2008 INSTRUCTOR: SALAM ABDUS SAMPLE PRELIM QUESTIONS (PRELIM #2) In total there will be 8 problems and 15 multiple choice questions. 8 problems would be worth 70 points and the 15 multiple choice questions would be worth 30 points. The

PAM 2100 Lecture 1 Fall 2008 Instructor: Salam Abdus Problem Set #2 Answer key Total Points: 10 Circle all of your final answers. Put your name and your section number at the top. #1) ACT scores are distributed normally with a mean = 28 and a standa

PAM 2100 Spring 2009 Problem Set #5 Answer Key Total Points: 10 Round your final answers to four decimal places, if necessary. #1) Let the random variable X be the number of repair calls that an appliance repair shop may receive during an hour. The d

PAM 2100 Lecture 1 Instructor: Salam Abdus Problem Set #3 Posted: September 23rd, 2008 Due: Tuesday, September 30th, 2008, at 1:25 pm
#1) Many high school students take either the SAT or the ACT. However, some students take both. Data was collected

PAM 2100 Lecture 1 Fall 2008 Instructor: Salam Abdus Problem Set #2 Posted: 16th September, 2008 Due: Tuesday, 23rd September, 2008, in class at 1:25 pm Circle all of your final answers. Put your name and your section number at the top. #1) ACT score

PAM 2100 Lecture 1 Fall 2008 Problem Set #5 Posted: October 23rd, 2008 Due Date: Tuesday, October 28th, 2008, in class Round your final answers to four decimal places, if necessary. #1) Let the random variable X be the number of repair calls that an

Introduction to Statistics- Prelim #1 PAM 2100 Spring 2009 Instructor: Salam Abdus STUDENTS NAME:_
SECTION NUMBER:_
CIRCLE YOUR ANSWERS TO THE MULTIPLE CHOICE QUESTIONS. ANSWER THE PROBLEMS IN THIS EXAMINATION. WHEN YOU START, MAKE SURE YOUR EXAM H

6.1
Estimating with Confidence
those who took the SAT math in 2003: mean= 519, sd= 115 give test to SRS of 500 California students: x = 461 (math) What can you say about the mean score in population of 385,000? x is an unbiased estimator of ( x = ) but ho

5.2
The Sampling Distribution of a Sample Mean
Figure 5.8 averages are less variable than individual observations averages are more normal than individual observations The mean and standard deviation of x x = mean of sample, = mean of population , 2 = pop

5.1
Sampling Distributions for Counts and Proportions
link between Chapter 4 (probability theory) and rest of book Statistical inference draws conclusions about a population or process on the basis of data. The data are summarized by statistics such as me

4.5
General Probability Rules Previous Probability Rules
1) The probability P(A) of any event A satisfies 0 P(A) 1. 2) All possible outcomes together must have probability 1. P(S) = 1. 3) Two events A and B are disjoint if they have no outcomes in common

4.4
Means and Variances of Random Variables Mean of a discrete random variable
Suppose that X is a discrete random variable whose distribution is Value of X Probability x1 x2 x3 xk p1 p2 p3 pk
To find the mean of X, multiply each possible value by its pro

4.3
Random Variables
random variable- a variable whose value is a numerical outcome of a random phenomenon toss coin 4 times- could record outcome as string of heads and tails (HTTH) let X be number of heads- X=2 (X is random variable) Discrete random var

4.2
Probability Models
probability model- a description of a random phenomenon in the language of mathematics the description of a random variable has two components: a list of possible outcomes a probability for each outcome The sample space S of a rando

4.1 Figure 4.1
Randomness
toss a coin- cant predict result in advance (results vary) a regular pattern emerges after many repetitions We call a phenomenon random if individual outcomes are uncertain but there is nonetheless a regular distribution of outco

3.3 Toward Statistical Inference Statistical inference is using a fact about a sample to estimate the truth about the whole population. A simple random sample (SRS) of size n consists of n individuals from the population chosen in such a way that every se

3.2 Sampling Design population- the entire group of individuals we want information about sample- the part of the population that we actually examine in order to gather information sample survey- survey a sample to gain info about the population voluntary

3.1
Design of Experiments
experimental units- individuals on which the experiment is done subjects- experimental subjects that are humans treatment- specific experimental condition applied to the units factors- explanatory variables in experiment levels-

6.2
Tests of Significance
EX 1 borrowers at private 4-year college: mean debt ( a )= $21,200 (survey result) borrowers at public 4-year college: mean debt ( b )= $17,100 (survey result) the difference $4100 ( a - b ) is fairly large/ but these numbers are

7.1
Inference for the Mean of a Population
the sampling distribution of x depends on when is unknown, we must estimate even though we are primarily interested in the sample standard deviation (s) is used to estimate the population standard deviation ()
)

7.2
Comparing Two Means
two-sample problems are among the most commonly encountered in statistics compare control group and treatment group Two-sample problems the goal of inference is to compare the responses in two groups each group is considered to be

5. The proportion of the American population that has O-negative blood is p=.16. If 12 people appear at random to give blood, what is the probability that exactly 3 of them have O-negative blood (rounded to four decimal places)? (Remember to express your

3. A researcher is interested in the relationship between test scores (TS) and the student teacher ratio (STR). Data was collected from 100 school districts. The average TS is 600 with a standard deviation of 12. The average STR is 20 with a standard devi

Problem Set #3 1. Consider the following table: Student Student 1 Student 2 Student 3 Math Score 2 2 8 Econ Score 19 20 21
Round the standard deviation of math scores to two decimal places. Round the standard deviation of Econ scores to two decimal places