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
Videos
Question
Chapter 13.10, Problem 53E
To determine
Construct a 95% confidence interval for difference between mean resistance for chemicals A and B.
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
A 30 month study is conducted to determine the difference in rates of accidents per month between two departments in an assembly plant. If a sample of 12 from the first department averaged 12.3 accidents per month with a standard deviation of 3.5, and a sample of 9 from the second department averaged 7.6 accidents per month with standard deviation of 3.4, find: The t-value for a 95% confidence interval is:
A. 2.09302
B. 1.724718
C. 2.08596
D. 1.729133
E. none of the preceding
Two ready mixed concrete companies are competing with each other. A research group randomly selected 5 concrete specimens from both corporations and tested the specimens to obtain the 28th-day cylinder compressive strengths. The resulting table is shown below
a) Use a lower 95% confidence bound to estimate the difference between the mean values of the 28th-day cylinder compressive strengths of these corporations.
b) Assume that the standard deviations of the data are sA= 5+(H/4) and sB= 7.5+(I/4) MPa for Company A and Company B, respectively. Construct a 95% confidence interval for thecomparison of the companies’ standard deviations.
H is 3 and I is 2
The trade magazine QR routinely checks the drive-through service times of fast-food restaurants. A 99% confidence interval that results from examining 719 customers in Taco Bell's drive-through has a lower bound of 159. 1 seconds and an upper bound of 162.1 seconds. Complete parts (a) through (c).
Chapter 13 Solutions
Mathematical Statistics with Applications
Ch. 13.2 - The reaction times for two different stimuli in a...Ch. 13.2 - Prob. 2ECh. 13.4 - State the assumptions underlying the ANOVA of a...Ch. 13.4 - Prob. 4ECh. 13.4 - Prob. 5ECh. 13.4 - Suppose that independent samples of sizes n1, n2,,...Ch. 13.4 - Four chemical plants, producing the same products...Ch. 13.4 - Prob. 8ECh. 13.4 - Prob. 9ECh. 13.4 - A clinical psychologist wished to compare three...
Ch. 13.4 - It is believed that women in the postmenopausal...Ch. 13.4 - If vegetables intended for human consumption...Ch. 13.4 - One portion of the research described in a paper...Ch. 13.4 - The Florida Game and Fish Commission desires to...Ch. 13.4 - Prob. 15ECh. 13.4 - An experiment was conducted to examine the effect...Ch. 13.5 - Prob. 17ECh. 13.5 - Refer to Exercise 13.17 and consider YiYi for i ...Ch. 13.5 - Refer to the statistical model for the one-way...Ch. 13.7 - Refer to Examples 13.2 and 13.3. a Use the portion...Ch. 13.7 - Refer to Examples 13.2 and 13.4. a Use the portion...Ch. 13.7 - a Based on your answers to Exercises 13.20 and...Ch. 13.7 - Refer to Exercise 13.7. a Construct a 95%...Ch. 13.7 - Prob. 24ECh. 13.7 - Prob. 25ECh. 13.7 - Prob. 26ECh. 13.7 - Prob. 27ECh. 13.7 - Prob. 28ECh. 13.7 - Prob. 29ECh. 13.7 - Prob. 30ECh. 13.7 - Prob. 31ECh. 13.7 - Prob. 32ECh. 13.7 - Prob. 33ECh. 13.7 - Prob. 34ECh. 13.7 - Prob. 35ECh. 13.8 - Prob. 36ECh. 13.8 - Prob. 37ECh. 13.8 - Prob. 38ECh. 13.8 - Prob. 39ECh. 13.8 - Prob. 40ECh. 13.9 - Prob. 41ECh. 13.9 - The accompanying table presents data on yields...Ch. 13.9 - Refer to Exercise 13.42. Why was a randomized...Ch. 13.9 - Prob. 44ECh. 13.9 - Prob. 45ECh. 13.9 - Prob. 46ECh. 13.9 - Prob. 47ECh. 13.9 - Prob. 48ECh. 13.9 - Prob. 49ECh. 13.9 - Prob. 50ECh. 13.9 - Prob. 51ECh. 13.10 - Prob. 52ECh. 13.10 - Prob. 53ECh. 13.10 - Prob. 54ECh. 13.10 - Refer to Exercise 13.46. Construct a 95%...Ch. 13.10 - Prob. 56ECh. 13.10 - Prob. 57ECh. 13.11 - Prob. 58ECh. 13.11 - Prob. 59ECh. 13.11 - Prob. 60ECh. 13.11 - Prob. 61ECh. 13.11 - Prob. 62ECh. 13.12 - Prob. 63ECh. 13.12 - Prob. 64ECh. 13.12 - Prob. 65ECh. 13.12 - Prob. 66ECh. 13.12 - Prob. 67ECh. 13.12 - Prob. 68ECh. 13.13 - Prob. 69ECh. 13.13 - Prob. 70ECh. 13.13 - Refer to Exercise 13.42. Answer part (a) by...Ch. 13.13 - Refer to Exercise 13.45. Answer part (b) by...Ch. 13 - Prob. 73SECh. 13 - Prob. 74SECh. 13 - Prob. 75SECh. 13 - Prob. 77SECh. 13 - A study was initiated to investigate the effect of...Ch. 13 - Prob. 79SECh. 13 - A dealer has in stock three cars (models A, B, and...Ch. 13 - In the hope of attracting more riders, a city...Ch. 13 - Prob. 84SECh. 13 - Prob. 85SECh. 13 - Prob. 86SECh. 13 - Prob. 87SECh. 13 - Prob. 88SECh. 13 - Prob. 89SECh. 13 - Prob. 90SECh. 13 - Prob. 92SECh. 13 - Prob. 94SE
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
- Suppose a researcher is interested in the effectiveness of a new drug intended to naturally increase hours of sleep for elderly patients experiencing insomnia. Suppose he collects information from a group of 64 patients and calculates a σ=.8 and a sample average of 6.4 hours of sleep. Is there sufficient evidence to reject the null hypothesis that his treatment is ineffective at increasing hours of sleep above 5 hours with 95% confidence?arrow_forwardTwo ready mixed concrete companies are competing with each other. A research group randomly selected 5 concrete specimens from both corporations and tested the specimens to obtain the 28th-day cylinder compressive strengths. The resulting table is shown below a) Use a lower 95% confidence bound to estimate the difference between the mean values of the 28th-day cylinder compressive strengths of these corporations. b) Assume that the standard deviations of the data are sA= 5+(3/4) and sB= 7.5+(2/4) MPa for Company A and Company B, respectively. Construct a 95% confidence interval for the comparison of the companies’ standard deviations. H is 3 and I is 2arrow_forwardThe following data represent the length of time, in days, to recovery for patients randomly treated with one of two medications to clear up severe bladder infections. Find a 90% confidence interval for the difference μ2−μ1 between in the mean recovery times for the two medications, assuming normal populations with equal variances. Medication 1 n1=12 x1=14 s21=1.8 Medication 2 n2=19 x2=16 s22=1.4arrow_forward
- In the macro relation between GDP and FDI, Dr Mudenda obtained the following valuesfrom a Stata output: FDI coefficient of 0.45; t-statistic of 3; and covariance (GDP, FDI)value of 0.41. In literature, this relationship between GDP and FDI has generally beenestablished to be statistically significant. Answer the following questions:i) Calculate the variance of the FDI variable and explain its implicationii) Use the confidence interval approach to test whether FDI’s influence on GDP isstatically significant or not in Dr Mudenda’s study. Use 5% level which gives 1.96critical values.iii) What is the expected value of the p-values for studies that have been conductedin literature?arrow_forwardA psychologist is studying the effects of lack of sleep on the performance of various perceptual-motor tasks. After a given period of sleep deprivation, a measurement of reaction time to an auditory stimulus was taken for each of 36 adult male subjects. The reaction times (in seconds) are summarized as follows: x = 1.82, s = 0.22 Previous psychological studies show that the true mean reaction time for non-sleep-deprived male subjects is 1.70 seconds. b) Find a 95% confidence interval for the mean reaction time for sleep-deprived male subjects.arrow_forwardRefer to Exercise 7.S.6. Construct a 95% confidence interval for the population mean reduction in stem length. Does the confidence interval indicate whether the effect of stress is “horticulturally important,” if “horticulturally important” is defined as a reduction in population mean stem length of at least 1 cm 2 cm 5 cmarrow_forward
- The management of a large national chain of 20 motels, each with 100 rooms, decided to estimate the mean cost per room of repairing damages made by its customers . A random sample of 31 vacated rooms was inspected by the management and indicated a mean repair cost Of tilde x =\$28.10 and a sample standard deviation of s=\$12.40 . Construct a 95\% confidence interval for the mean repair cost u for the 2000 motel rooms .arrow_forward11.36 Use the data from Exercise 11.22.a. Estimate the mean time to run 10 km for athletes having a treadmill time of11 minutes.b. Place a 95% confidence interval on the mean time to run 10 km for athleteshaving a treadmill time of 11 minutes.arrow_forward1. A recent survey showed that from a sample of 500 packages delivered by a Postal Service, 480were delivered on time. a) Construct a 95% confidence interval for the proportion of all packages that are deliveredon time by the Postal Service.arrow_forward
- In a study of maternal cigarette smoking and bone density in newborns, 77 infants of mothers who smoked had a mean bone mineral content of 0.098 g/cm3 (s1 = 0.026 g/cm3). The 161 infants whose mothers did not smoke had a mean bone mineral content of 0.095 g/cm3 (s2 = 0.025 g/cm3). Calculate the 95% confidence interval for µ1 - µ2arrow_forward1. A study is run comparing HDL cholesterol levels between men who exercise regularly and those who do not. The data are shown below. Regular Exercise N Mean Std DevYes 35 48.5 12.5No 120 56.9 11.9 Generate a 95% confidence interval for the difference in mean HDL levels between men who exercise regularly and those who do not.arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons Inc
Probability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage Learning
Statistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSON
The Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. Freeman
Introduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman
MATLAB: An Introduction with Applications
Statistics
ISBN:9781119256830
Author:Amos Gilat
Publisher:John Wiley & Sons Inc
Probability and Statistics for Engineering and th...
Statistics
ISBN:9781305251809
Author:Jay L. Devore
Publisher:Cengage Learning
Statistics for The Behavioral Sciences (MindTap C...
Statistics
ISBN:9781305504912
Author:Frederick J Gravetter, Larry B. Wallnau
Publisher:Cengage Learning
Elementary Statistics: Picturing the World (7th E...
Statistics
ISBN:9780134683416
Author:Ron Larson, Betsy Farber
Publisher:PEARSON
The Basic Practice of Statistics
Statistics
ISBN:9781319042578
Author:David S. Moore, William I. Notz, Michael A. Fligner
Publisher:W. H. Freeman
Introduction to the Practice of Statistics
Statistics
ISBN:9781319013387
Author:David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:W. H. Freeman
Hypothesis Testing using Confidence Interval Approach; Author: BUM2413 Applied Statistics UMP;https://www.youtube.com/watch?v=Hq1l3e9pLyY;License: Standard YouTube License, CC-BY
Hypothesis Testing - Difference of Two Means - Student's -Distribution & Normal Distribution; Author: The Organic Chemistry Tutor;https://www.youtube.com/watch?v=UcZwyzwWU7o;License: Standard Youtube License