APPLIED STAT.IN BUS.+ECONOMICS
6th Edition
ISBN: 9781259957598
Author: DOANE
Publisher: RENT MCG
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 9, Problem 2CR
(a) Explain the difference between the null hypothesis and the alternative hypothesis, (b) How is the null hypothesis chosen (why is it “null")?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
3. Bayesian Inference – Updating Beliefs
A medical test for a rare disease has the following characteristics:
Sensitivity (true positive rate): 99%
Specificity (true negative rate): 98%
The disease occurs in 0.5% of the population.
A patient receives a positive test result.
Questions:
a) Define the relevant events and use Bayes’ Theorem to compute the probability that the patient actually has the disease.b) Explain why the result might seem counterintuitive, despite the high sensitivity and specificity.c) Discuss how prior probabilities influence posterior beliefs in Bayesian inference.d) Suppose a second, independent test with the same accuracy is conducted and is also positive. Update the probability that the patient has the disease.
4. Linear Regression - Model Assumptions and Interpretation
A real estate analyst is studying how house prices (Y) are related to house size in square feet (X). A simple
linear regression model is proposed:
The analyst fits the model and obtains:
•
Ŷ50,000+150X
YBoB₁X + €
•
R² = 0.76
• Residuals show a fan-shaped pattern when plotted against fitted values.
Questions:
a) Interpret the slope coefficient in context.
b) Explain what the R² value tells us about the model's performance.
c) Based on the residual pattern, what regression assumption is likely violated? What might be the
consequence?
d) Suggest at least two remedies to improve the model, based on the residual analysis.
5. Probability Distributions – Continuous Random Variables
A factory machine produces metal rods whose lengths (in cm) follow a continuous uniform distribution on the interval [98, 102].
Questions:
a) Define the probability density function (PDF) of the rod length.b) Calculate the probability that a randomly selected rod is shorter than 99 cm.c) Determine the expected value and variance of rod lengths.d) If a sample of 25 rods is selected, what is the probability that their average length is between 99.5 cm and 100.5 cm? Justify your answer using the appropriate distribution.
Chapter 9 Solutions
APPLIED STAT.IN BUS.+ECONOMICS
Ch. 9.2 - If you repealed a hypothesis test 1,000 times (in...Ch. 9.2 - Define Type I and Type II errors for each...Ch. 9.2 - A firm decides to test its employees for illegal...Ch. 9.2 - A hotel installs smoke detectors with adjustable...Ch. 9.2 - What is the consequence of a false negative in an...Ch. 9.2 - Prob. 6SECh. 9.3 - A manufacturer claims that its compact fluorescent...Ch. 9.3 - Prob. 8SECh. 9.3 - Prob. 9SECh. 9.3 - The average age of a part-time seasonal employee...
Ch. 9.3 - Prob. 11SECh. 9.3 - Prob. 12SECh. 9.4 - Find the zcalc test statistic for each hypothesis...Ch. 9.4 - Prob. 14SECh. 9.4 - Prob. 15SECh. 9.4 - Prob. 16SECh. 9.4 - Green Beam Ltd. claims that its compact...Ch. 9.4 - The mean potassium content of a popular sports...Ch. 9.4 - Calculate the test statistic and p-value for each...Ch. 9.4 - Determine the p-value for each test statistic. a....Ch. 9.4 - Procyon Mfg. produces tennis balls. Weights are...Ch. 9.4 - The mean arrival rate of flights at OHare Airport...Ch. 9.4 - Prob. 23SECh. 9.4 - The Scottsdale fire department aims to respond to...Ch. 9.4 - The lifespan of xenon metal halide arc-discharge...Ch. 9.4 - Discuss the issues of statistical significance and...Ch. 9.4 - The target activation force of the buttons on a...Ch. 9.5 - Find the tcalc test statistic for each hypothesis...Ch. 9.5 - Find the critical value of Students t for each...Ch. 9.5 - Find the critical value of Students t for each...Ch. 9.5 - Find the tcalc test statistic for each hypothesis...Ch. 9.5 - Estimate the p-value as a range using Appendix D...Ch. 9.5 - Prob. 33SECh. 9.5 - Prob. 34SECh. 9.5 - Prob. 35SECh. 9.5 - The manufacturer of an airport baggage scanning...Ch. 9.5 - Prob. 37SECh. 9.5 - The average weight of a package of rolled oats is...Ch. 9.5 - Prob. 39SECh. 9.5 - Prob. 40SECh. 9.5 - Prob. 41SECh. 9.5 - Prob. 42SECh. 9.5 - Prob. 43SECh. 9.6 - Interpret each p-value in your own words: a....Ch. 9.6 - Prob. 45SECh. 9.6 - Prob. 46SECh. 9.6 - May normality of the sample proportion p be...Ch. 9.6 - Prob. 48SECh. 9.6 - In a hospitals shipment of 3,500 insulin syringes,...Ch. 9.6 - Prob. 50SECh. 9.6 - Prob. 51SECh. 9.6 - The recent default rate on all student loans is...Ch. 9.6 - Prob. 53SECh. 9.6 - A Realtor claims that no more than half of the...Ch. 9.6 - BriteScreen, a manufacturer of 19-inch LCD...Ch. 9.6 - Perfect pitch is the ability to identify musical...Ch. 9.7 - A quality expert insects 400 items to test whether...Ch. 9.7 - Prob. 58SECh. 9.7 - For a certain wine, the mean pH (a measure of...Ch. 9.7 - Repeat the previous exercise, using = .05. For...Ch. 9.8 - A sample of size n = 15 has variance s2 = .35. At ...Ch. 9.8 - Prob. 62SECh. 9.8 - A sample of size n = 19 has variance s2 = .1.96....Ch. 9.8 - Prob. 64SECh. 9.8 - Prob. 65SECh. 9 - (a) List the steps in testing a hypothesis, (b)...Ch. 9 - (a) Explain the difference between the null...Ch. 9 - (a) Why do we say fail to reject H0 instead of...Ch. 9 - (a) Define Type I error and Type II error. (b)...Ch. 9 - (a) Explain the difference between a left-tailed...Ch. 9 - Prob. 6CRCh. 9 - Prob. 7CRCh. 9 - (a) Why do we prefer low values for and ? (b) For...Ch. 9 - Prob. 10CRCh. 9 - Prob. 11CRCh. 9 - (a) Explain what a p-value means. Give an example...Ch. 9 - Prob. 13CRCh. 9 - (a) What does a power curve show? (b) What factors...Ch. 9 - (a) In testing a hypothesis about a variance, what...Ch. 9 - Suppose you always reject the null hypothesis,...Ch. 9 - Suppose the judge decides to acquit all...Ch. 9 - High blood pressure, if untreated, can lead to...Ch. 9 - A nuclear power plant replaces its ID card...Ch. 9 - A test-preparation company advertises that its...Ch. 9 - Prob. 71CECh. 9 - Prob. 72CECh. 9 - Prob. 73CECh. 9 - Pap smears are a test for abnormal cancerous and...Ch. 9 - Prob. 75CECh. 9 - Prob. 76CECh. 9 - Malcheon Health Clinic claims that the average...Ch. 9 - The sodium content of a popular sports drink is...Ch. 9 - A can of peeled whole tomatoes is supposed to...Ch. 9 - At Ajax Spring Water, a half-liter bottle of soft...Ch. 9 - Prob. 81CECh. 9 - Prob. 82CECh. 9 - A U.S. dime weighs 2.268 grams when minted. A...Ch. 9 - A coin was flipped 60 times and came up heads 38...Ch. 9 - Prob. 85CECh. 9 - Prob. 86CECh. 9 - Prob. 87CECh. 9 - Prob. 88CECh. 9 - Prob. 89CECh. 9 - Prob. 90CECh. 9 - Prob. 91CECh. 9 - Prob. 92CECh. 9 - The average service time at a Noodles Company...Ch. 9 - Prob. 94CECh. 9 - Prob. 95CECh. 9 - Beer shelf life is a problem for brewers and...Ch. 9 - Prob. 97CECh. 9 - Prob. 99CECh. 9 - Prob. 100CECh. 9 - Prob. 101CECh. 9 - Prob. 102CECh. 9 - An experimental medication is administered to 16...Ch. 9 - The historical on-time percentage for Amtraks...Ch. 9 - After 7 months, none of 238 angioplasty patients...Ch. 9 - A certain brand of flat white interior latex paint...Ch. 9 - Prob. 107CECh. 9 - Prob. 108CECh. 9 - Prob. 109CE
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.Similar questions
- 2. Hypothesis Testing - Two Sample Means A nutritionist is investigating the effect of two different diet programs, A and B, on weight loss. Two independent samples of adults were randomly assigned to each diet for 12 weeks. The weight losses (in kg) are normally distributed. Sample A: n = 35, 4.8, s = 1.2 Sample B: n=40, 4.3, 8 = 1.0 Questions: a) State the null and alternative hypotheses to test whether there is a significant difference in mean weight loss between the two diet programs. b) Perform a hypothesis test at the 5% significance level and interpret the result. c) Compute a 95% confidence interval for the difference in means and interpret it. d) Discuss assumptions of this test and explain how violations of these assumptions could impact the results.arrow_forward1. Sampling Distribution and the Central Limit Theorem A company produces batteries with a mean lifetime of 300 hours and a standard deviation of 50 hours. The lifetimes are not normally distributed—they are right-skewed due to some batteries lasting unusually long. Suppose a quality control analyst selects a random sample of 64 batteries from a large production batch. Questions: a) Explain whether the distribution of sample means will be approximately normal. Justify your answer using the Central Limit Theorem. b) Compute the mean and standard deviation of the sampling distribution of the sample mean. c) What is the probability that the sample mean lifetime of the 64 batteries exceeds 310 hours? d) Discuss how the sample size affects the shape and variability of the sampling distribution.arrow_forwardA biologist is investigating the effect of potential plant hormones by treating 20 stem segments. At the end of the observation period he computes the following length averages: Compound X = 1.18 Compound Y = 1.17 Based on these mean values he concludes that there are no treatment differences. 1) Are you satisfied with his conclusion? Why or why not? 2) If he asked you for help in analyzing these data, what statistical method would you suggest that he use to come to a meaningful conclusion about his data and why? 3) Are there any other questions you would ask him regarding his experiment, data collection, and analysis methods?arrow_forward
- Businessarrow_forwardWhat is the solution and answer to question?arrow_forwardTo: [Boss's Name] From: Nathaniel D Sain Date: 4/5/2025 Subject: Decision Analysis for Business Scenario Introduction to the Business Scenario Our delivery services business has been experiencing steady growth, leading to an increased demand for faster and more efficient deliveries. To meet this demand, we must decide on the best strategy to expand our fleet. The three possible alternatives under consideration are purchasing new delivery vehicles, leasing vehicles, or partnering with third-party drivers. The decision must account for various external factors, including fuel price fluctuations, demand stability, and competition growth, which we categorize as the states of nature. Each alternative presents unique advantages and challenges, and our goal is to select the most viable option using a structured decision-making approach. Alternatives and States of Nature The three alternatives for fleet expansion were chosen based on their cost implications, operational efficiency, and…arrow_forward
- The following ordered data list shows the data speeds for cell phones used by a telephone company at an airport: A. Calculate the Measures of Central Tendency from the ungrouped data list. B. Group the data in an appropriate frequency table. C. Calculate the Measures of Central Tendency using the table in point B. 0.8 1.4 1.8 1.9 3.2 3.6 4.5 4.5 4.6 6.2 6.5 7.7 7.9 9.9 10.2 10.3 10.9 11.1 11.1 11.6 11.8 12.0 13.1 13.5 13.7 14.1 14.2 14.7 15.0 15.1 15.5 15.8 16.0 17.5 18.2 20.2 21.1 21.5 22.2 22.4 23.1 24.5 25.7 28.5 34.6 38.5 43.0 55.6 71.3 77.8arrow_forwardII Consider the following data matrix X: X1 X2 0.5 0.4 0.2 0.5 0.5 0.5 10.3 10 10.1 10.4 10.1 10.5 What will the resulting clusters be when using the k-Means method with k = 2. In your own words, explain why this result is indeed expected, i.e. why this clustering minimises the ESS map.arrow_forwardwhy the answer is 3 and 10?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Algebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:Cengage
Algebra & Trigonometry with Analytic Geometry
Algebra
ISBN:9781133382119
Author:Swokowski
Publisher:Cengage
Statistics 4.1 Introduction to Inferential Statistics; Author: Dr. Jack L. Jackson II;https://www.youtube.com/watch?v=QLo4TEvBvK4;License: Standard YouTube License, CC-BY