Ask Question, Ask an Expert

+1-415-315-9853

info@mywordsolution.com

Ask Statistics and Probability Expert

Instructions: This problem set is due by the end of class on Thursday, November 15th. You can either hand in a paper copy, or email a copy to amcquoid@u.edu. When you submit through email, please title the file "firstname_lastname_ps5". NO LATE homework will be acknowledged. The complete answer comprises not just a numerical (or graphical or tabular) answer, however an interpretation of the result. You are expected to give thorough answers to problems which ask for a discussion, interpretation or description. The overall problem set grade depends mainly on your capability to describe.

problem: (Anderson, Sweeney, and Williams, 11th ed, 8.8)

The National Quality Research Center at University of Michigan offers a quarterly measure of consumer opinions regarding products and services (The Wall Street Journal, February 18, 2003). The survey of 10 restaurants in the Fast Food/Pizza group showed a sample mean customer satisfaction index of 71. Past data point out that the population standard deviation of the index has been relatively stable with σ = 5

a) What assumption must the researcher be willing to make if a margin of error is desired?
b) Using 95% confidence, determine the margin of error?
c) Determine the margin of error if 99% confidence is desired?

problem: (Anderson, Sweeney, and Williams, 11th ed, 8.10)

Playbill magazine reported that the mean annual household income of its readers is $119,155 (Playbill, January 2006). Suppose this estimate of the mean annual household income is based on the sample of 80households, and based on past studies, the population standard deviation is known to be σ = $30; 000.

a) Make a 90% confidence interval estimate of the population mean.
b) Make a 95% confidence interval estimate of the population mean.
c) Make a 99% confidence interval estimate of the population mean.
d) Discuss what happens to the width of confidence interval as the confidence level is raised.

Does this result seem reasonable? Describe.

problem: (Anderson, Sweeney, and Williams, 11th ed, 8.16)

The mean number of hours of flying time for pilots at the Continental Airlines is 49 hours per month (The Wall Street Journal, February 25, 2003). Suppose that this mean was based on actual flying times for a sample of 100 Continental pilots and that the sample standard deviation was 8.5 hours.

a) At 95% confidence, determine the margin of error?
b) Determine the 95% confidence interval estimate of the population mean flying time for the pilots?

c) The mean number of hours of flying time for the pilots at United Airlines is 36 hours per month. Use your outcomes from part (b) to discuss differences between the flying times for the pilots at the two 1airlines. The Wall Street Journal reported United Airlines as having the highest labor cost among all airlines. Does the information in this exercise give insight as to why United Airlines might expect the higher labor costs?

problem: (Anderson, Sweeney, and Williams, 11th ed, 8.19)

The average cost per night of a hotel room in the New York City is $273 (SmartMoney, March 2009). Suppose this estimate is based on the sample of 45 hotels and which the sample standard deviation is $65.

a) With 95% confidence, determine the margin of error?
b) Determine the 95% confidence interval estimate of the population mean?
c) Two years ago, the average cost of a hotel room in the New York City was $229. Discuss the change in cost over two-year period.

problem: (Anderson, Sweeney, and Williams, 11th ed, 8.26)

The average cost of gallon of unleaded gasoline in the Greater Cincinnati was reported to be $2.41 (The Cincinnati Enquirer, February 3, 2006). Throughout periods of rapidly modifying prices, the newspaper samples service stations and prepares reports on gasoline prices frequently. Suppose the standard deviation is $.15 for the price of a gallon of unleaded regular gasoline, and recommend the suitable sample size for the newspaper to use if they wish to report a margin of error at 95% confidence.

a) Assume that the desired margin of error is $.07.
b) Assume that the desired margin of error is $.05.
c) Assume that the desired margin of error is $.03.

problem: (Anderson, Sweeney, and Williams, 11th ed, 8.38)

According to Thomson Financial, through January 25, 2006, the majority of companies reporting profits had beaten estimates (Business Week, February 6, 2006). The sample of 162 companies showed 104 beat estimates, 29 matched estimates, and 29 fell short.

a) What is the point estimate of the proportion which fell short of estimates?
b) Determine the margin of error and provide a 95% confidence interval for the proportion which beat estimates.
c) How big a sample is required if the desired margin of error is .05?

Statistics and Probability, Statistics

  • Category:- Statistics and Probability
  • Reference No.:- M9255

Have any Question? 


Related Questions in Statistics and Probability

How did some indian religious leaders add certain christian

How did some Indian religious leaders add certain Christian teachings to their traditional beliefs?

Consider a decision-maker whose subjective probability

Consider a decision-maker whose subjective probability distribution over the set of possible states Ω is p = (p(s)) We ask him to tell us his subjective probability distribution, but he can lie and report any distributio ...

A consumer advocacy group tested the on-air lifetimes a

A consumer advocacy group tested the "on-air" lifetimes a random sample of 241 cell phone batteries. The mean lifetime was 3.2 hours with a standard deviation of 0.1 hours. The lifetimes are approximately bell-shaped. Es ...

1 a producer specifies that the mean lifetime of a certain

1. A producer specifies that the mean lifetime of a certain type of battery is at least 240 hours. A sample of 18 such batteries yielded the following data. 237             242             232 242             248         ...

Part a - excel instructions for chi-square tests carrying

Part A - Excel Instructions for Chi-square Tests Carrying out Chi-square (χ 2 ) tests of independence We are considering prisoner behaviour data. There is a prison with six wings each with 100 prisoners. Prisoner behavio ...

Imagine that you have collected the following set of iq

Imagine that you have collected the following set of IQ scores: 110 124 100 125 104 119 98 130 76 95 143 90 132 102 125 96 99 78 100 80 112 112 103 88 94 108 88 132 87 119 109 104 104 100 119 99 135 128 92 110 90 92 120 ...

Corrections for phase 4in confidence interval calculations

CORRECTIONS FOR PHASE 4 In confidence interval calculations, sqrt(364) goes in the bottom for E; this has thrown off your intervals - too narrow; t should be negative in the hypothesis test, but your conclusion is correc ...

Suppose that a certain college class contains 49 students

Suppose that a certain college class contains 49 students. Of these, 24 are seniors, 26 are English majors, and 9 are neither. A student is selected at random from the class. (a) What is the  probability  that the studen ...

Suppose that a certain college class contains 49 students

Suppose that a certain college class contains 49 students. Of these, 24 are seniors, 26 are English majors, and 9 are neither. A student is selected at random from the class. (a) What is the  probability  that the studen ...

The mean incubation time for a type of fertilized egg kept

The mean incubation time for a type of fertilized egg kept at 100.7° F is 22days. Suppose that the incubation times are approximately normally distributed with a standard deviation of 2 days. (a) The probability that a r ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

WalMart Identification of theory and critical discussion

Drawing on the prescribed text and/or relevant academic literature, produce a paper which discusses the nature of group

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro