In a random sample of 85 automobile engine crankshaft bearings, 10 have a sur face finish that is rougher than the spe ci fications allow. Therefore, a point estimate of the proportion of bearings in the population that exceeds the roughness specification is p = x/n = 10/85 = 0.12. Compute for a 95% two-sided confidence interval of p?

In a random sample of 85 automobile engine crankshaft bearings, 10 have a sur face finish that is rougher than the spe ci fications allow. Therefore, a point estimate of the proportion of bearings in the population that exceeds the roughness specification is p = x/n = 10/85 = 0.12. Compute for a 95% two-sided confidence interval of p?

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

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:
The EPA wants to test a randomly selected sample of nn water specimens and estimate the mean daily rate of pollution produced by a mining operation. If the EPA wants a 90.3% confidence interval with a margin of error of 1 milligram per liter (mg/L), how many water specimens are required in the sample? Assume prior knowledge indicates that pollution readings in water samples taken during a day have been approximately normally distributed with a standard deviation of 4 (mg/L). n=
A random sample of 50 roundtrip flights between New York and Chicago has an average airfare of $400 with a sample standard deviation of $50.0. The critical value for an 95% confidence interval around this sample mean is ________.
A random sample of 11 shearing pins is taken in a study of the Rockwell hardness of the pin head. Measurements on the Rockwell hardness are made for each of the 11, yielding an average value of 48.50 with a sample standard deviation of 1.6. Assuming the measurements to be normally distributed, construct a 95% confidence interval for the mean Rockwell hardness.
In a sample of n=19 lichen specimens, the researchers found the mean and standard deviation of the amount of the radioactive element, cesium-137, that was present to be 0.009 and 0.006 microcurie per milliliter, respectively. Suppose the researchers want to increase the sample size in order to estimate the mean μ to within 0.002 microcurie per milliliter of its true value, using a 95% confidence interval.
During a routine check of the fluoride content of Gotham City's water supply, the given results were obtained from replicate analyses of a single sample: 0.513 mg/L0.513 mg/L , 0.487 mg/L0.487 mg/L , 0.511 mg/L0.511 mg/L , 0.489 mg/L0.489 mg/L , and 0.519 mg/L0.519 mg/L . Determine the mean and 90% confidence interval for the average fluoride concentration in this sample. Report the mean and the confidence interval with three significant figures.
In an evaluation of a method for the determination of fluorene in seawater, a synthetic sample of seawater was spiked with 50 ng ml−1 of fluorene. Ten replicate determinations of the fluorene concentration in the sample had a mean of 49.5 ng ml−1 with a standard deviation of 1.5 ng ml−1. Calculate the 95% confidence limits of the mean. Is the spiked value of 50 ng ml−1 within the 95% confidence limits?
A large multi-branch bank is affiliated with both the MasterCard and Visa credit cards. For a random sample of 100 MasterCard cardholders, it is observed that the average month-end account balance is R682.58 with a sample standard deviation of R307.05. For a random sample of 100 Visa cardholders, the average month-end account balance is R550.55 with a sample standard deviation of R265.29. The 90% confidence interval for the mean difference between the month-end account balances for the two types of credit card holders (rounded to three decimals) is:
On the Navajo Reservation, a random sample of 214 permanent dwellings in the Fort Defiance region showed that 58 were traditional Navajo hogans. In the Indian Wells region, a random sample of 151 permanent dwellings showed that 19 were traditional hogans. Let p1 be the population proportion of all traditional hogans in the Fort Defiance region, and let p2 be the population proportion of all traditional hogans in the Indian Wells region. (a) Find a 90% confidence interval for p1 – p2. (Use 3 decimal places.) lower limit upper limit
An epidemiologist needs to estimate the proportion of residents of Okeechobee county that have been infected with COVID-19. Determine the most conservative estimate of the sample size required to limit the margin of error to within 0.069 of the population proportion for a 99% confidence interval.Round the solution up to the nearest whole number.
In a sample of 40 water specimens taken from a construction site 26 contained detectable level of lead. An 80% confidence interval for the proportion of water specimens that contains detectable levels of lead is
In monitoring lead in the air after an explosion at a battery factory, it is found that the amount of lead (in ug/m3) over a 6 day period had a standard error of 2.57. Find the margin of error that corresponds to a 95% confidence interval.