STAT 1124 Statistical Methods I Confidence Intervals CH 14
Albert Wong, Ph.D. Langara College January 2009
Statistical Inference
Statistical Inference: Methods for drawing conclusions about a population from sample data Two major Types of inference: Esti
STAT 1124 Section 2 Assignment 8 No Due Date Model Answers 1. Question 20.16 Page 506 H0: p = 0.5 Ha: p > 0.5 Set = 0.05 phat = 22/32 = 0.6875 Test statistic = z = (0.6875-0.5)/sqrt(0.5*(1-0.5)/32) = 2.12 p-value = P(z > 2.12) = 0.0170 Since the p-value i
STAT 1124 Section 2 Quiz 1 January 20, 2009 You have 20 minutes to complete the following
1. A research study was developed to compare the effect of a new nutritional supplement on weight loss. 40 people were recruited for the study and randomly assigned
STAT 1124 Assignment 1 Due Tuesday, January 20, 2009 Model Answers
1. For each of the following situations, describe the population, type of sample, sample size, and variable of interest: a) An administrator in Langara College selected a random sample of
STAT 1124 Section 2 Assignment 5 Due Wednesday, March 4, 2009 Model Answers You can complete these questions by using Excel or Statgraphics. 1. Question 5.26, Page 140. Using Excel, we obtain the following scatterplot:
Exercise 5.26 Page 140
70 68 Siste's
Basic Organization of Music Chapter 2 Answer Keys
Exercis e 2.1
Listen to the following pairs of notes, then answer the following questions. Each example will be played twice. Which is the lowest no te, the firs t or the second? Is the pair of notes an oc
STAT 1124
Statistical Methods I Correlation I Ch 4
Albert Wong, Ph.D. Langara College January 2009
Bivariate Analysis
Analysis of two variables simultaneously (bivariate analysis) Descriptive Statistics:
Scatterplot Coefficient of Correlation (correlati
Stats 1124
HW 3
You may do this homework in pairs. If you do so, hand in only one paper with the names of both
partners.
Hospital management have collected data on the number of monthly staff-hours (HOURS) needed to
run the anaesthesiology department and
STAT 1124
HW 2
You may do this assignment in pairs. If you do, hand in only one paper with both your and
your partner's names.
The file earthquake.xlsx contains data on 50 destructive earthquakes since 1905. You can
find it posted in D2L. Two of the varia
POPULATION, PARAMETER, SAMPLE, STATISTICS
DEFINITIONS:
A population is the set of all elements (e.g., people, cars, invoices) we want to learn
something about.
A parameter is a number that describes a specific characteristic of the population.
A sample is
DATA AND SCALES OF MEASUREMENT
Elements and variables:
An element is an item (person, box, car, etc.) on which information is collected. A variable is
the information collected from each element. A data set is usually arranged in a spreadsheet,
where each
OBTAINING DATA
Once we have selected the elements/individuals to be studied, using a sampling design,
there are two ways to obtain data from them. We can conduct either an observational study
or an experiment.
OBSERVATION VERSUS EXPERIMENT:
An observation
NORMAL DISTRIBUTION
A data set is said to be Normally distributed if its theoretical density curve can be described by the
function (which is also known as the Normal curve, or bell curve):
f x =
1
1 x
exp
2
2
2
for all real x
Characteristics of Normal
STAT 1124
Project Proposal
As part of this course, you are required to carry out a statistical study. This includes planning,
data collection, data analysis, and the presentation of your findings and methods. This is a
chance for you to apply the statisti
Exercises on Sampling, Bias, & Experiment
1. To study the use of marijuana among youth the police department visited a number of
colleges and high schools, and selected a sample of students to be interviewed. The
interview was done by a uniformed police o
SAMPLING AND BIAS
A sampling frame, also called the target population, is the set of elements from which the
sample is actually taken. Ideally, the sampling frame should be identical with the population of
interest. In practice, however, this is not alway
Statistics team
presentation
Sikander
Sandhu
Tejeshwar
Randhawa
TABLE OF CONTENTS
SLIDES 3
Statement of study
SLIDES 4
Objectives
SLIDES 5
Method and source of data
SLIDES 6
Why quasi random sampling?
SLIDES 7
Statistical methods used
SLIDES 8-11
Statisti
Stat 1124 Week 2 Assignment Answer Key
1.
In some states of U.S.A., the law requires drivers to turn on their vehicle headlights when driving in
rainy days, between 8am and 6pm. A new highway patrol would like to see what percentage of them
does not follo
Statistical Methods I Unit 2 Experiments
Albert Wong, Ph.D. Langara College January 2009
Experiments
A study that imposes some treatment on individuals in order to observe and statistically compare their responses The purpose is to study whether the trea
Limitations and Improvements The limitation of our study is the relatively small sample used (102 houses within Vancouver East and Vancouver West). If more time is allowed, we could examine a larger sample of houses and compare the results from Vancouver
STAT 1124 Assignment 3 Model Answers
Question 3.4, Page 69 a. Mean is C, Median is B b. Mean is B, Median is B c. Mean is A, Median is B Question 3.30, Page 86 Draw a picture before you attempt to solve the problem a. 0.0122 b. 1-0.0122 = 0.9878 c. 1-0.96
STAT 1124 Section 2 Assignment 4 Due Tuesday, February 24, 2009 All questions for this assignment are from the text. 1. Question 4.24, Page 108. You must calculate the correlation by hand. Use the Decision Table for correlation in the supplement to answer
STAT 1124 Section 2 Assignment 6 Due Monday, March 23, 2009
1. An experiment was carried out in order to see what factors are associated with the rotting of tomato during storage. One of the factors considered was the temperature of the storage space, eit
STAT 1124 Section 2 Assignment 7 Due Thursday April 23, 2009 Model Answers
1. Question 14.24, Page 358 n = (0.258*0.79/0.2)2 103.5 104 2. Question 14.30, Page 360 a. A 99% confidence interval is 137 2.58*(65/sqrt(269) = 137 10.209 b. The sample is a simpl
Page 1 STAT 1124 Section 2 Mid Term 1 February 12, 2009 Model Answers You have 55 minutes to complete the test. Justify your answers in order to receive full credit The total number of points is 28 1. Daily rainfall (in millimeters) was recorded over a 30
Page 1
STAT 1124 Section 2 Mid Term 2 March 2, 2009 Model Answers You have 55 minutes to complete the test. Justify your answers in order to receive full credit The total number of points is 30 1. In a biological experiment, the following has been obtaine
Page 1
STAT 1124 Section 2 Mid Term 3 March 25, 2009 Model Answers You have 55 minutes to complete the test. The total number of points is 20 1. In a research study for cell phone usage while driving, one of the key research questions is whether there is
STAT 1124 Section 2 Quiz 2 February 2, 2009 You have 20 minutes to complete the following
Name: Student ID:
1. Given the following table that summarizes a sample:
xi 15.9 16.0 16.4 16.7 16.8 16.9 17.0 17.0 17.1 17.2 17.2 17.3 17.5 17.7 17.8 17.9 18.3 18.4
STAT 1124 Section 2 Quiz 3 February 24, 2009 Model Answers You have 20 minutes to complete the following:
Name: Student ID:
1. Drilling down beneath a lake in Alaska yields chemical evidence of past changes in climate. Biological silicon, left by the skel