Mathematical Statistics with Applications
7th Edition
ISBN: 9780495110811
Author: Dennis Wackerly, William Mendenhall, Richard L. Scheaffer
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Question
Chapter 8.9, Problem 98E
To determine
Obtain the formula for a confidence interval for the population standard deviation
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A quality characteristic of a product is normally distributed with mean μ and standard deviation σ = 1. Speci-
fications on the characteristic are 6≤x≤8. A unit that falls within specifications on this quality characteristic
results in a profit of Co. However, if x 8, the profit is -C2. Find the value
ofμ that maximizes the expected profit.
A) The output voltage of a power supply is normally distributed with mean 5 V and standard deviation 0.02 V. If
the lower and upper specifications for voltage are 4.95 V and 5.05 V, respectively, what is the probability that a
power supply selected at random conform to the specifications on voltage?
B)
Continuation of A. Reconsider the power supply manufacturing process in A. Suppose
We wanted to improve the process. Can shifting the mean reduce the number of nonconforming units produced?
How much would the process variability need to be reduced in order to have all but one out of 1000 units conform
to the specifications?
der to complete the Case X
T Civil Service Numerical Test Sec X T Casework Skills Practice Test
Maseline
Vaseline
x +
euauthoring.panpowered.com/DeliveryWeb/Civil Service Main/84589a48-6934-4b6e-a6e1-a5d75f559df9?transferToken-News NGSSON
The table below shows the best price available for various items from 4 uniform suppliers. The prices do not include VAT
(charged at 20%).
Item
Waterproof boots
A1-Uniforms (£)Best Trade (£)Clothing Tech (£)Dress Right (£)
59.99
39.99
59.99
49.99
Trousers
9.89
9.98
9.99
11.99
Shirts
14.99
15.99
16.99
12.99
Hi-Vis vest
4.49
4.50
4.00
4.00
20.00
25.00
19.50
19.99
Hard hats
A company needs to buy a set of 12 uniforms which includes 1 of each item. If the special offers are included
which supplier is cheapest?
OOO
A1-Uniforms
Best Trade
Clothing Tech
Q Search
+
**
109
8
CO*
F10
Home
F11
F12
6
Chapter 8 Solutions
Mathematical Statistics with Applications
Ch. 8.2 - Using the identity ()=[E()]+[E()]=[E()]+B(), Show...Ch. 8.2 - a. If is an unbiased estimator for , what is B()?...Ch. 8.2 - Suppose that is an estimator for a parameter and...Ch. 8.2 - Refer to Exercise 8.1. a. If is an unbiased...Ch. 8.2 - Refer to Exercises 8.1 and consider the unbiased...Ch. 8.2 - Suppose that E(1)=E(2)=, V(1)=12, and V(2)=22....Ch. 8.2 - Consider the situation described in Exercise 8.6....Ch. 8.2 - Suppose that Y1, Y2, Y3 denote a random sample...Ch. 8.2 - Suppose that Y1, Y2,, Yn constitute a random...Ch. 8.2 - The number of breakdowns per week for a type of...
Ch. 8.2 - Let Y1, Y2, , Yn denote a random sample of size n...Ch. 8.2 - The reading on a voltage meter connected to a test...Ch. 8.2 - We have seen that if Y has a binomial distribution...Ch. 8.2 - Prob. 14ECh. 8.2 - Let Y, Y2,,Yn denote a random sample of size n...Ch. 8.2 - Suppose that Y1, Y2,,Yn constitute a random sample...Ch. 8.2 - If Y has a binomial distribution with parameters n...Ch. 8.2 - Let Y1, Y2, , Yn denote a random sample of size n...Ch. 8.2 - Prob. 19ECh. 8.2 - Suppose that Y1, Y2, Y3, Y4 denote a random sample...Ch. 8.4 - An investigator is interested in the possibility...Ch. 8.4 - An increase in the rate of consumer savings...Ch. 8.4 - The Environmental Protection Agency and the...Ch. 8.4 - A study was conducted to compare the mean number...Ch. 8.4 - The Mars twin rovers, Spirit and Opportunity,...Ch. 8.4 - A random sample of 985 likely votersthose who are...Ch. 8.4 - In a study of the relationship between birth order...Ch. 8.4 - Sometimes surveys provide interesting information...Ch. 8.4 - Refer to Exercise 8.29. Give the point estimate...Ch. 8.4 - In a study to compare the perceived effects of two...Ch. 8.4 - An auditor randomly samples 20 accounts receivable...Ch. 8.4 - Refer to Exercise 8.32. From the data given on the...Ch. 8.4 - We can place a 2-standard-deviation bound on the...Ch. 8.4 - Prob. 35ECh. 8.4 - Prob. 36ECh. 8.4 - Refer to Exercise 8.36. An engineer observes n =...Ch. 8.4 - Prob. 38ECh. 8.5 - Suppose that the random variable Y has a gamma...Ch. 8.5 - Suppose that the random variable Y is an...Ch. 8.5 - Suppose that Y is normally distributed with mean 0...Ch. 8.5 - Prob. 42ECh. 8.5 - Prob. 43ECh. 8.5 - Let Y have probability density function...Ch. 8.5 - Refer to Exercise 8.44. a Use the pivotal quantity...Ch. 8.5 - Refer to Example 8.4 and suppose that Y is a...Ch. 8.5 - Refer to Exercise 8.46. Assume that Y1, Y2, , Yn...Ch. 8.5 - Prob. 48ECh. 8.6 - Refer to Example 8.8. In this example, p1 and p2...Ch. 8.6 - Prob. 51ECh. 8.6 - Prob. 52ECh. 8.6 - Prob. 53ECh. 8.6 - Prob. 54ECh. 8.6 - Prob. 55ECh. 8.6 - Is Americas romance with movies on the wane? In a...Ch. 8.6 - Refer to Exercise 8.29. According to the result...Ch. 8.6 - The administrators for a hospital wished to...Ch. 8.6 - When it comes to advertising, tweens are not ready...Ch. 8.6 - What is the normal body temperature for healthy...Ch. 8.6 - A small amount of the trace element selenium, from...Ch. 8.6 - The following statistics are the result of an...Ch. 8.6 - Most Americans love participating in or at least...Ch. 8.6 - In a CNN/USA Today/Gallup Poll, 1000 Americans...Ch. 8.6 - For a comparison of the rates of defectives...Ch. 8.6 - Historically, biology has been taught through...Ch. 8.6 - One suggested method for solving the...Ch. 8.6 - Prob. 68ECh. 8.6 - Prob. 69ECh. 8.7 - Let Y be a binomial random variable with parameter...Ch. 8.7 - A state wildlife service wants to estimate the...Ch. 8.7 - Telephone pollsters often interview between 1000...Ch. 8.7 - Refer to Exercise 8.59. How many tweens should...Ch. 8.7 - Prob. 74ECh. 8.7 - Prob. 75ECh. 8.7 - Refer to the comparison of the daily adult intake...Ch. 8.7 - Prob. 77ECh. 8.7 - Refer to Exercise 8.65. How many items should be...Ch. 8.7 - Refer to Exercise 8.66. a Another similar study is...Ch. 8.8 - Although there are many treatments for bulimia...Ch. 8.8 - The carapace lengths of ten lobsters examined in a...Ch. 8.8 - Scholastic Assessment Test (SAT) scores, which...Ch. 8.8 - Chronic anterior compartment syndrome is a...Ch. 8.8 - Organic chemists often purify organic compounds by...Ch. 8.8 - Two new drugs were given to patients with...Ch. 8.8 - The Environmental Protection Agency (EPA) has...Ch. 8.8 - Refer to Exercise 8.88. Another common...Ch. 8.8 - Do SAT scores for high school students differ...Ch. 8.8 - Seasonal ranges (in hectares) for alligators were...Ch. 8.8 - Solid copper produced by sintering (heating...Ch. 8.8 - Prob. 93ECh. 8.8 - Suppose that we obtain independent samples of...Ch. 8.9 - The EPA has set a maximum noise level for heavy...Ch. 8.9 - In Exercise 8.81, we gave the carapace lengths of...Ch. 8.9 - Suppose that S2 is the sample variance based on a...Ch. 8.9 - Prob. 98ECh. 8.9 - Prob. 99ECh. 8.9 - Industrial light bulbs should have a mean life...Ch. 8.9 - In laboratory work, it is desirable to run careful...Ch. 8.9 - The ages of a random sample of live university...Ch. 8.9 - A precision instrument is guaranteed to read...Ch. 8 - Prob. 104SECh. 8 - Prob. 105SECh. 8 - In a controlled pollination study involving Phlox...Ch. 8 - Prob. 107SECh. 8 - Prob. 108SECh. 8 - To estimate the proportion of unemployed workers...Ch. 8 - Prob. 110SECh. 8 - Prob. 111SECh. 8 - Prob. 112SECh. 8 - Prob. 113SECh. 8 - Prob. 114SECh. 8 - Prob. 115SECh. 8 - Do we lose our memory capacity as we get older? In...Ch. 8 - Prob. 117SECh. 8 - Prob. 118SECh. 8 - Prob. 119SECh. 8 - Two methods for teaching reading were applied to...Ch. 8 - Prob. 121SECh. 8 - Prob. 122SECh. 8 - Prob. 123SECh. 8 - Prob. 124SECh. 8 - Prob. 125SECh. 8 - Prob. 126SECh. 8 - Prob. 127SECh. 8 - Prob. 128SECh. 8 - Prob. 129SECh. 8 - Prob. 130SECh. 8 - Refer to Exercises 1.129 and 1.130. S2 and S2 are...Ch. 8 - Prob. 132SECh. 8 - Prob. 133SECh. 8 - Prob. 134SECh. 8 - Prob. 135SECh. 8 - Prob. 136SE
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
- to complete the Case × T Civil Service Numerical Test Sec x T Casework Skills Practice Test + Vaseline euauthoring.panpowered.com/DeliveryWeb/Civil Service Main/84589a48-b934-4b6e-a6e1-a5d75f559df9?transferToken=MxNewOS NGFSPSZSMOMzuz The table below shows the best price available for various items from 4 uniform suppliers. The prices do not include VAT (charged at 20%). Item A1-Uniforms (£)Best Trade (£)Clothing Tech (£)Dress Right (£) Waterproof boots 59.99 39.99 59.99 49.99 Trousers 9.89 9.98 9.99 11.99 Shirts 14.99 15.99 16.99 12.99 Hi-Vis vest 4.49 4.50 4.00 4.00 20.00 25.00 19.50 19.99 Hard hats A company needs to buy a set of 12 uniforms which includes 1 of each item. If the special offers are included, which supplier is cheapest? O O O O A1-Uniforms Best Trade Clothing Tech Dress Right Q Search ENG L UK +0 F6 四吧 6 78 ㄓ F10 9% * CO 1 F12 34 Oarrow_forwardCritics review films out of 5 based on three attributes: the story, the special effects and the acting. The ratings of four critics for a film are collected in the table below.CriticSpecialStory rating Effects rating Acting rating Critic 14.44.34.5Critic 24.14.23.9Critic 33.943.4Critic 44.24.14.2Critic 1 also gave the film a rating for the Director's ability. If the average of Critic 1's ratings was 4.3 what rating did they give to the Director's ability?3.94.04.14.24.3arrow_forwardTwo measurements are made of some quantity. For the first measurement, the average is 74.4528, the RMS error is 6.7441, and the uncertainty of the mean is 0.9264. For the second one, the average is 76.8415, the standard deviation is 8.3348, and the uncertainty of the mean is 1.1448. The expected value is exactly 75. 13. Express the first measurement in public notation. 14. Is there a significant difference between the two measurements? 1 15. How does the first measurement compare with the expected value? 16. How does the second measurement compare with the expected value?arrow_forward
- A hat contains slips of paper numbered 1 through 6. You draw two slips of paper at random from the hat,without replacing the first slip into the hat.(a) (5 points) Write out the sample space S for this experiment.(b) (5 points) Express the event E : {the sum of the numbers on the slips of paper is 4} as a subset of S.(c) (5 points) Find P(E)(d) (5 points) Let F = {the larger minus the smaller number is 0}. What is P(F )?(e) (5 points) Are E and F disjoint? Why or why not?(f) (5 points) Find P(E ∪ F )arrow_forwardIn addition to the in-school milk supplement program, the nurse would like to increase the use of daily vitamin supplements for the children by visiting homes and educating about the merits of vitamins. She believes that currently, about 50% of families with school-age children give the children a daily megavitamin. She would like to increase this to 70%. She plans a two-group study, where one group serves as a control and the other group receives her visits. How many families should she expect to visit to have 80% power of detecting this difference? Assume that drop-out rate is 5%.arrow_forwardA recent survey of 400 americans asked whether or not parents do too much for their young adult children. The results of the survey are shown in the data file. a) Construct the frequency and relative frequency distributions. How many respondents felt that parents do too much for their adult children? What proportion of respondents felt that parents do too little for their adult children? b) Construct a pie chart. Summarize the findingsarrow_forward
- The average number of minutes Americans commute to work is 27.7 minutes (Sterling's Best Places, April 13, 2012). The average commute time in minutes for 48 cities are as follows: Click on the datafile logo to reference the data. DATA file Albuquerque 23.3 Jacksonville 26.2 Phoenix 28.3 Atlanta 28.3 Kansas City 23.4 Pittsburgh 25.0 Austin 24.6 Las Vegas 28.4 Portland 26.4 Baltimore 32.1 Little Rock 20.1 Providence 23.6 Boston 31.7 Los Angeles 32.2 Richmond 23.4 Charlotte 25.8 Louisville 21.4 Sacramento 25.8 Chicago 38.1 Memphis 23.8 Salt Lake City 20.2 Cincinnati 24.9 Miami 30.7 San Antonio 26.1 Cleveland 26.8 Milwaukee 24.8 San Diego 24.8 Columbus 23.4 Minneapolis 23.6 San Francisco 32.6 Dallas 28.5 Nashville 25.3 San Jose 28.5 Denver 28.1 New Orleans 31.7 Seattle 27.3 Detroit 29.3 New York 43.8 St. Louis 26.8 El Paso 24.4 Oklahoma City 22.0 Tucson 24.0 Fresno 23.0 Orlando 27.1 Tulsa 20.1 Indianapolis 24.8 Philadelphia 34.2 Washington, D.C. 32.8 a. What is the mean commute time for…arrow_forwardMorningstar tracks the total return for a large number of mutual funds. The following table shows the total return and the number of funds for four categories of mutual funds. Click on the datafile logo to reference the data. DATA file Type of Fund Domestic Equity Number of Funds Total Return (%) 9191 4.65 International Equity 2621 18.15 Hybrid 1419 2900 11.36 6.75 Specialty Stock a. Using the number of funds as weights, compute the weighted average total return for these mutual funds. (to 2 decimals) % b. Is there any difficulty associated with using the "number of funds" as the weights in computing the weighted average total return in part (a)? Discuss. What else might be used for weights? The input in the box below will not be graded, but may be reviewed and considered by your instructor. c. Suppose you invested $10,000 in this group of mutual funds and diversified the investment by placing $2000 in Domestic Equity funds, $4000 in International Equity funds, $3000 in Specialty Stock…arrow_forwardThe days to maturity for a sample of five money market funds are shown here. The dollar amounts invested in the funds are provided. Days to Maturity 20 Dollar Value ($ millions) 20 12 30 7 10 5 6 15 10 Use the weighted mean to determine the mean number of days to maturity for dollars invested in these five money market funds (to 1 decimal). daysarrow_forward
- c. What are the first and third quartiles? First Quartiles (to 1 decimals) Third Quartiles (to 4 decimals) × ☑ Which companies spend the most money on advertising? Business Insider maintains a list of the top-spending companies. In 2014, Procter & Gamble spent more than any other company, a whopping $5 billion. In second place was Comcast, which spent $3.08 billion (Business Insider website, December 2014). The top 12 companies and the amount each spent on advertising in billions of dollars are as follows. Click on the datafile logo to reference the data. DATA file Company Procter & Gamble Comcast Advertising ($billions) $5.00 3.08 2.91 Company American Express General Motors Advertising ($billions) $2.19 2.15 ETET AT&T Ford Verizon L'Oreal 2.56 2.44 2.34 Toyota Fiat Chrysler Walt Disney Company J.P Morgan a. What is the mean amount spent on advertising? (to 2 decimals) 2.55 b. What is the median amount spent on advertising? (to 3 decimals) 2.09 1.97 1.96 1.88arrow_forwardMartinez Auto Supplies has retail stores located in eight cities in California. The price they charge for a particular product in each city are vary because of differing competitive conditions. For instance, the price they charge for a case of a popular brand of motor oil in each city follows. Also shown are the number of cases that Martinez Auto sold last quarter in each city. City Price ($) Sales (cases) Bakersfield 34.99 501 Los Angeles 38.99 1425 Modesto 36.00 294 Oakland 33.59 882 Sacramento 40.99 715 San Diego 38.59 1088 San Francisco 39.59 1644 San Jose 37.99 819 Compute the average sales price per case for this product during the last quarter? Round your answer to two decimal places.arrow_forwardConsider the following data and corresponding weights. xi Weight(wi) 3.2 6 2.0 3 2.5 2 5.0 8 a. Compute the weighted mean (to 2 decimals). b. Compute the sample mean of the four data values without weighting. Note the difference in the results provided by the two computations (to 3 decimals).arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill
Big Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
Big Ideas Math A Bridge To Success Algebra 1: Stu...
Algebra
ISBN:9781680331141
Author:HOUGHTON MIFFLIN HARCOURT
Publisher:Houghton Mifflin Harcourt
Statistics 4.1 Point Estimators; Author: Dr. Jack L. Jackson II;https://www.youtube.com/watch?v=2MrI0J8XCEE;License: Standard YouTube License, CC-BY
Statistics 101: Point Estimators; Author: Brandon Foltz;https://www.youtube.com/watch?v=4v41z3HwLaM;License: Standard YouTube License, CC-BY
Central limit theorem; Author: 365 Data Science;https://www.youtube.com/watch?v=b5xQmk9veZ4;License: Standard YouTube License, CC-BY
Point Estimate Definition & Example; Author: Prof. Essa;https://www.youtube.com/watch?v=OTVwtvQmSn0;License: Standard Youtube License
Point Estimation; Author: Vamsidhar Ambatipudi;https://www.youtube.com/watch?v=flqhlM2bZWc;License: Standard Youtube License