Chapter 07, Section 7.4, Problem 040X Incorrect.Johnson Electronics Corporation makes electric tubes. It is known that the standard deviation of the lives of these tubes is 145 hours. The company's research department takes a sample of 105such tubes and finds that the mean life of thesé tubes is 2500 hours. What is the probability that this sample mean is within 22 hours of the mean life of all túbes produced by this company?Round your answer to four decimal places.3686Pthe tolerance is +/-2%SHOW HINTunQuestion Attempts: 1 of 2 usedSAVE FOR LATERSUBMIT ANSWERoncionSation156ction19ection022powered byMapleNetPowered by MapleNet www.maplesoft.comVersion 4.24.20.1ent I Privacy Policy © 2000-2020 John Wiley & Sons, Inc. All Rights Reserved. A Division of John Wiley & Sons, Inc.MacBook AirDIIDDF12F11F10F980FBF7F6F4F5F3F2F1&%2324%97124P* CO

Given: x=2500σ=145n=105 The probability that the sample mean is within 22 hours of the mean life of…

Johnson Electronics Corporation makes electric tubes. It is known that the standard deviation of the lives of these tubes is 145 hours. The company's research department takes a sample of 105 such tubes and finds that the mean life of thesé tubes is 2500 hours. What is the probability that this sample mean is within 22 hours of the mean life of all túbes produced by this company?

Johnson Electronics Corporation makes electric tubes. It is known that the standard deviation of the lives of these tubes is 145 hours. The company's research department takes a sample of 105 such tubes and finds that the mean life of thesé tubes is 2500 hours. What is the probability that this sample mean is within 22 hours of the mean life of all túbes produced by this company?

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

The scores on a standardized test are normally distributed with a mean of 90 and standard deviation of 10. What test score is 0.6 standard deviations above the mean?
Lazurus Steel Corporation produces iron rods that are supposed to be 36 inches long. The machine that makes these rods does not produce each rod exactly 36 inches long. The lengths of the rods are normally distributed and vary slightly. It is known that when the machine is working properly, the mean length of the rods is 36 inches. The standard deviation of the lengths of all rods produced on this machine is always equal to 0.035 inch. The quality control department at the company takes a sample of 20 such rods every week, calculates the mean length of these rods, and tests the null hypothesis, μ = 36 inches, against the alternative hypothesis, μ ≠ 36 inches. If the null hypothesis is rejected, the machine is stopped and adjusted. A recent sample of 20 rods produced a mean length of 36.015 inches. Calculate the p-value for this test of hypothesis. Based on this p-value, will the quality control inspector decide to stop the machine and adjust it if he chooses the maximum probability of…
It takes an average of 8 minutes for blood to begin clotting after an injury. An EMT wants to see if the average will increase if the patient is immediately told the truth about the injury. The EMT randomly selected 62 injured patients to immediately tell the truth about the injury and noticed that they averaged 8.5 minutes for their blood to begin clotting after their injury. Their standard deviation was 3.1 minutes. What can be concluded at the the a = 0.05 level of significance? a. For this study, we should use t-test for a population mean b. The null and alternative hypotheses would be: Ho: Hv Select an answer v Н: Select an answer v c. The test statistic t v (please show your answer to 3 decimal places.) d. The p-value = (Please show your answer to 4 decimal places.) e. The p-value is >v f. Based on this, we should Select an answer v the null hypothesis. g. Thus, the final conclusion is that ... O The data suggest that the population mean is not significantly greater than 8 at a =…
Suppose a researcher wants to know if the average diastolic blood pressure in Irish-Americans is different than the average diastolic blood pressure in the general population. Note that the average diastolic blood pressure in the general population is 70 mmHG. The researcher recruits 30 Irish-Americans into this particular study and then measures each of their diastolic blood pressures (mmHG). The sample standard deviation in this sample is 3.0. Note that we do not know the population standard deviation (commonly denoted σ). If we want to build a 95% confidence interval, what is the "t-value" used in the interval? Recall intervals are of the form
Two friends, Karen and Jodi, work different shifts for the same ambulance service. They wonder if the different shifts average different numbers of calls. Looking at past records, Karen determines from a random sample of 40 shifts that she had a mean of 4.8 calls per shift. She knows that the population standard deviation for her shift is 1.4 calls. Jodi calculates from a random sample of 31 shifts that her mean was 5.6 calls per shift. She knows that the population standard deviation for her shift is 1.2 calls. Test the claim that there is a difference between the mean numbers of calls for the two shifts at the 0.05 level of significance. Let Karen's shifts be Population 1 and let Jodi's shifts be Population 2. Step 2 of 3 : Compute the value of the test statistic. Round your answer to two decimal places.
It seems these days that college graduates who are employed full-time work more than 40-hour weeks. Data are available that can help us decide if this is true. A survey was recently sent to a group of adults selected at random. There were 13 respondents who were college graduates employed full-time. The mean number of hours worked per week by these 13 respondents was 42 hours, with a standard deviation of 8 hours. Assume that the population of hours worked per week by college graduates employed full-time is normally distributed with mean u. Can we conclude that u is greater than 40 hours? Use the 0.05 level of significance. Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the table. (If necessary, consult a list of formulas.) (a) State the null hypothesis H, and the alternative hypothesis H1. p H. :0 H :0 (b) Determine the type of test statistic to use. (Choose one) ▼…
It seems these days that college graduates who are employed full-time work more than 40-hour weeks. Data are available that can help us decide if this is true. A survey was recently sent to a group of adults selected at random. There were 10 respondents who were college graduates employed full-time. The mean number of hours worked per week by these 10 respondents was 47 hours, with a standard deviation of 8 hours. Assume that the population of hours worked per week by college graduates employed full-time is normally distributed with mean u. Can we conclude that u is greater than 40 hours? Use the 0.05 level of significance. Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the table. (If necessary, consult a list of formulas.) (a) State the null hypothesis H, and the alternative hypothesis H. H, :0 H :0 (b) Determine the type of test statistic to use. (Choose one) ▼ OSO…
Two friends, Karen and Jodi, work different shifts for the same ambulance service. They wonder if the different shifts average different numbers of calls. Looking at past records, Karen determines from a random sample of 41 shifts that she had a mean of 5.1 calls per shift. She knows that the population standard deviation for her shift is 1.5 calls. Jodi calculates from a random sample of 32 shifts that her mean was 5.8 calls per shift. She knows that the population standard deviation for her shift is 1.2 calls. Test the claim that there is a difference between the mean numbers of calls for the two shifts at the 0.01 level of significance. Let Karen's shifts be Population 1 and let Jodi's shifts be Population 2. Step 2 of 3 : Compute the value of the test statistic. Round your answer to two decimal places.
It seems these days that college graduates who are employed full-time work more than 40-hour weeks. Data are available that can help us decide if this is true. A survey was recently sent to a group of adults selected at random. There were 15 respondents who were college graduates employed full-time. The mean number of hours worked per week by these 15 respondents was 43 hours, with a standard deviation of 8 hours. Assume that the population of hours worked per week by college graduates employed full-time is normally distributed with mean μ. Can we conclude that μ is greater than 40 hours? Use the 0.05 level of significance. State the null hypothesis H0 and the alternative hypothesis H1 Find the t-test df & Solve the t-test value Find the critical value Can we conclude, at the 0.05 level of significance, that the mean number of hours worked per week by college graduates is greater than 40 hours? Yes or No?
Forty refrigerators from two different models of a refrigerator manufacturer are compared to see if the smaller model uses less energy than the larger model. The energy was measured in kilowatt hours per month (kwh/mo). From years of testing these models, it is known that the standard deviation of kwh/mo is 34 kwh/mo for the smaller model and 40 kwh/mo for the larger one. From this survey, the sample means and standard deviations are 125 and 34, and 90 and 40, respectively. If we conduct a hypothesis test, the p-value is Group of answer choices 0.0000 0.0010 0.0004 0.0002
A manufacturer of bolts has a quality-control policy that requires it to destroy any bolts that are more than 2 standard deviations from the mean. The quality-control engineer knows that the bolts coming off the assembly line have mean length of 10 cm with a standard deviation of 0.05 cm. For what lengths will a bolt be destroyed?
The average age of senators in the 108th Congress was 62 years. If the standard deviation was 12.5 years, find the z-scores corresponding to the oldest and youngest senators of age 86 and 46. Round z scores to two decimal places.