18+Test3Prep - BIT 2405 Quantitative Methods I BIT 2405...

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Unformatted text preview: BIT 2405 Quantitative Methods I BIT 2405 Quantitative Methods I Test 3 Preparation Chapters 9 & 11.1 This Week and Next. This Week and Next. Lectures Hawkes Today Optional HW911 and Optional Required Quiz 3 Required due @ 9 am 11/19 NOW IS NOW IS THE TIME THE TIME tto ASK o ASK FOR FOR HELP! HELP! Schedule Next Week. Schedule Next Week. Day Monday 11/16 Tuesday 11/17 Content Time Help Session 11:00 am ROB105 Early Test 3 3:30 pm TORG2150 Wednesday 11/18 Thursday Test 3 11/19 11:00 am ROB105 3:30 pm TORG2150 Day Monday 11/16 Tuesday 11/17 Schedule Next Week. You MUST EMAIL ME by MONDAY You MUST EMAIL ME by MONDAY Content @ 9AM and get Time permission from me 9AM to change your test from your Scheduled Time. Scheduled Help Session 11:00 am ROB105 Early Test 3 3:30 pm TORG2150 Your Scheduled Test Time IS on Your Wednesday Thursday in the Time for which you are 11/18 ENROLLED. ENROLLED. Thursday 11/19 Test 3 11:00 am ROB105 3:30 pm TORG2150 Questions? Questions? Test 3 Test 3 s 25 Multiple Choice Questions • Covers Chapters 9 and 11.1 • Mostly “calculations” with looking up in Tables s 50 Minutes to Complete Chapter 9 Hypothesis Testing 9.1 9.2 9.3 9.4 Developing Null and Alternative Hypotheses Type I and Type II Errors Population Mean: σ Known NOT ON NOT Population Mean: σ Unknown THE TEST THE 9.5 Population Proportion Chapter 11 Chapter 11 Inferences About Population Variances 11.1 Inference about a Population Variance 11.2 Inferences about the Variances of Two Populations Interval Estimation: Interval Estimation: σ Only σ2 & σ Only 2 ( n − 1) s2 ( n − 1) s2 ≤ σ2 ≤ 2 2 χ α /2 χ (1− α / 2) 1. 2. 3. 4. σ (n − 1) s 2 (n − 1) s 2 ≤σ ≤ 2 2 χα /2 χ (1−α / 2) Determine whether it’s variance or standard deviation Calculate α/2 and the Degrees of Freedom, df = (n­1) Look up the two χ 2 values and Crunch the numbers. Hypothesis Testing 1. Three Basic Forms of the Null Hypothesis whether it’ s μ, p, or σ. (μ i s shown below) Determine the basic test required & SKETCH IT! H 0 : µ ≥ µ0 H 0 : µ ≤ µ0 H 0 : µ = µ0 One­tailed (lower­tail) One­tailed (upper­tail) Two­tailed α α α/2 α/2 Hypothesis Testing Hypothesis Testing 1. 2. Determine the basic test required & SKETCH IT! Determine the Population Parameter of interest. μ p σ 2 Hypothesis Testing Hypothesis Testing 1. 2. Determine what the basic test required & SKETCH IT! Determine the Population Parameter of interest. a. If μ, determine if σ­known or σ­unknown p μ σ-known σ-unknown σ 2 Hypothesis Testing Hypothesis Testing 1. Calculate the Test Statistic. p μ σ-known zobs = x − µ σ/ n 0 σ 2 σ-unknown t obs = x − µ s/ n 0 z obs = ˆ p − p0 p0 (1 − p0 ) n χ 2 obs (n − 1) s 2 = σ 02 Hypothesis Testing Hypothesis Testing 1. “Reject” or “Do Not Reject” the Null Hypothesis using either the p­value test ­ OR ­ critical value test I ’ ll use the σ-known case to illustrate. I’ Lower­Tailed Test About a Population Mean: σ Known s p­value Approach p­Value < α , so reject H0. α = .10 Sampling distribution of zobs = x − µ 3. Compare σ/ n p­value = .0 7 2 2. “ Look Up” p-value 2. z z = 0 obs σ known 0 ­1.46 1. Calculate Zobs Lower­Tailed Test About a Population Mean: σ Known s Critical Value Approach Zobs < ­Zα , so reject H0. α = .10 Sampling distribution of zobs = x − µ σ/ n 3. Compare Z’ s 2. Calculate Zobs z = obs σ known ­1.46 0 z ­zα = ­1.28 0 1. “ Look Up” Zα Upper­Tailed Test About a Population Mean: σ Known s p­Value Approach Sampling distribution of zobs = x − µ p­Value <α , so reject H0. α = .04 0 σ/ n p­Value = .0 1 1 z 0 σ known zα = 1.75 z = obs 2.29 Upper­Tailed Test About a Population Mean: σ Known s Critical Value Approach Sampling distribution of zobs = x − µ 0 σ/ n Reject H0 Do Not Reject H0 0 σ known α = .0 5 zα = 1.645 z Two­Tailed Tests About a Population Mean: Two­Tailed Tests About a Population Mean: σ Known p­Value Approach 1/2 p ­value = .0031 α = 0.03 α /2 = .015 α /2 = .015 z ­zα/2 = ­2.17 0 zα/2 = 2.17 z = 2.74 obs Two­Tailed Tests About a Population Mean: σ Known Critical Value Approach Sampling distribution of zobs = x − µ 0 σ/ n Reject H0 Reject H0 Do Not Reject H0 α/2 = .015 ­2.17 α/2 = .015 0 2.17 z Keep Track of What Population Parameter You Are Working With. p μ σ-known zobs = x − µ σ/ n 0 Z-Tables σ-unknown t obs = x − µ s/ n 0 T-Tables σ χ 2-Tables Z-Tables z obs = ˆ p − p0 p0 (1 − p0 ) n 2 χ 2 obs (n − 1) s 2 = σ 02 Keep Track of What Test Is Needed. 1. Determine the basic test required & SKETCH IT! H 0 : µ ≥ µ0 H 0 : µ ≤ µ0 H 0 : µ = µ0 One­tailed One­tailed (lower­tail) One­tailed (upper­tail) Two­tailed α α α/2 α/2 Keep Track of What You’re Looking Up. p μ σ-known Z-Tables σ-unknown T-Tables Z-Tables σ 2 χ 2-Tables Keep Track of What You’re Looking Up. p μ σ-known Z-Tables • Symmetrical Symmetrical • Centered on 0 Centered • Lower Tail Given L ower σ-unknown Z-Tables σ 2 Keep Track of What You’re Looking Up. p μ σ-known • • • • • σ-unknown Symmetrical Symmetrical Centered on 0 Centered Upper Tail Given Upper Degrees of Freedom Degrees Columns are Areas Columns T-Tables σ 2 Keep Track of What You’re Looking Up. p μ σ-known σ-unknown • NOT Symmetrical NOT • NOT Centered on 0 NOT •All Positive Values • Upper Tail Given Upper • Degrees of Freedom Degrees • Columns are Areas Columns σ 2 χ 2-Tables Formula Sheet Formula Sheet For the Test For the Test s s s s VT Photo ID Calculator • (Any calculator including graphing) Pencils (#2) NOT ALLOWED (Includes) • Phone • Computer • Books, notes nor any other materials... You will be given a FORMULA SHEET when you come to the Test. You cannot use your own! Cheating and YOUR WORD. Cheating and YOUR WORD. The Rules 1. You must turn in all pages of the exam and the scantron form or you will receive a ZERO on this exam. 2. Make sure you correctly code in the test form and your Student ID on your scantron form. 3. You may not discuss this exam during the exam nor outside of this classroom until all of Dr. Jones's BIT2405 students have completed their exam. 4. You must pledge the exam or you will receive a zero. 5. The honor code is in effect for all exams. Pledge the exam to indicate you have neither given nor received help. This is a closed­ book, closed­notes exam. Sharing calculators is a violation of the honor code. Presence of a cell phone is a violation of the honor code. Cheating and YOUR WORD. Cheating and YOUR WORD. The Rules I pledge that I have neither given nor received help on this exam. I will not discuss this exam with anyone in Dr. Jones’s BIT2405 classes until after all students have taken the exam. The last exams will be finished by 5 pm on The Thursday, November 19th. Thursday, Cheating and YOUR WORD. Cheating and YOUR WORD. Close Quarters. s Keep your SCANTRON FORM COVERED unless you are writing on it. s Keep your eyes on your own papers. s The GAs and I are VIGILANT about watching you and taking names of anyone suspected of cheating. • I will follow the honor code to the fullest extent. s NO HATS ALLOWED! During the Test During the Test s I will not answer questions during the test! • If you are missing a page or something like that, then please ask me. Otherwise, I don’t answer questions about the questions or the test in general. s I will not discuss the test with you after you finish. • If you have a concern about a question on the test, please email me and I will address that the following week. s If you think none of the answers is correct, I suggest you RE­ READ the PROBLEM to make sure you got the right Formula. Grades Grades s I will post grades in Scholar and email you when I’ve posted them. • Hope to have this done at the latest by Monday, November 23rd. s I will NOT email your grade to you. DON’T FORGET… DON’T FORGET… s REQUIRED QUIZ 3 on Scholar goes away @ 9 am on Thursday, November 19th. s EMAIL me by Monday @ 9 am if you want to SWITCH TEST TIMES. Don’ t forget Don’ your CALCULATOR CALCULATOR ! s BRING YOUR CALCULATOR to the Test. s Post Questions on the DISCUSSION BOARDS on BLACKBOARD if you need help beyond the sessions. Questions? Questions? ...
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This note was uploaded on 08/30/2011 for the course ART 3514 taught by Professor Dhbannan during the Summer '03 term at Virginia Tech.

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