/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q.8 聽Engine parts Here are measurem... [FREE SOLUTION] | 91影视

91影视

Engine parts Here are measurements (in millimeters) of a critical dimension on an SRS of 16of the more than 200auto engine crankshafts produced in one day:

224.120, 224.001, 224.017,223.982,223.989,223.960,224.089,223.987,223.976,223.902,223.980,224.098,224.057,223.913,223.999

(a) Construct and interpret a 95%confidence interval for the process mean at the time these crankshafts were produced.

(b) The process mean is supposed to be =224but can drift away from this target during production. Does your interval from part (a) suggest that the process mean has drifted? Explain.

- Determine the sample size required to obtain a level Cconfidence interval for a population mean with a specified margin of error.

Short Answer

Expert verified

(a) The sample is 3535

(b) Yes

Step by step solution

01

Part (a) Step 1: Given Information

Given in the question that,

224.120
224.001
224.017
223.982
223.989
223.961
223.960
224.089
223.987
223.976
223.902
223.980
224.098
224.057
223.913
223.999

we have to construct and interpret a 95%confidence interval for the process mean at the time these crankshafts were produced.

02

Part (a) Step 2:  Explanation 

The formula to compute the confidence interval is:

x-t2sn<<x+t2sn

The confidence interval using Ti-83calculator could be computed as:

Thus there is95%probability that the population mean is between223.97and227.03

03

Part (b) Step 1: Given Information 

The process mean is supposed to be =224 but can drift away from this target during production .we have to find that Does interval from part (a) suggest that the process mean has drifted .

04

Part (b) Step 2:  Explanation 

From the above part, it is known that the population mean process is between 223.97and224.03Since, the interval is containing 224 it could be said that the process mean has drifted.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Many teens have posted profiles on sites such as Facebook and My Space. A sample survey asked random samples of teens with online profiles if they included false information in their profiles. Of 170younger teens (ages 12to 14) polled, 117said 鈥淵es.鈥 Of 317older teens (ages 15to 17) polled, 152 said 鈥淵es.鈥6 A 95% confidence interval for the difference in the population proportions (younger teens 鈥 older teens) is 0.120 to 0.297. Interpret the confidence interval and the confidence level

Researchers were interested in comparing two methods for estimating tire wear. The first method used the amount of weight lost by a tire. The second method used the amount of wear in the grooves of the tire. A random sample of 16tires was obtained. Both methods were used to estimate the total distance traveled by each tire. The table below provides the two estimates (in thousands of miles) for each tire.

(a) Construct and interpret a 95%confidence interval for the mean difference in the estimates from these two methods in the population of tires.

(b) Does your interval in part (a) give convincing evidence of a difference in the two methods of estimating tire wear? Justify your answer.

role="math" localid="1649913699288" TireWeightGrooveTireWeightGroove145.935.7930.423.1241.939.21027.323.7337.531.11120.420.9433.428.11224.516.1531.024.01320.919.9630.528.71418.915.2730.925.91513.711.5831.923.31611.411.2

School vouchers A national opinion poll found that 44% of all American adults agree that parents should be given vouchers that are good for education at any public or private school of their choice. The result was based on a small sample.

(a) How large an SRS is required to obtain a margin of error of 0.03(that is, 3%) in a 99% con铿乨ence interval? Answer this question using the previous poll鈥檚 result as the guessed value for p.

(b) Answer the question in part (a) again, but this time use the conservative guess p=0.5. By how much do the two sample sizes differ?

63. Give it some gas! Computers in some vehicles calculate various quantities related to performance. One of these is fuel efficiency, or gas mileage, usually expressed as miles per gallon (mpg). For one vehicle
equipped in this way, the miles per gallon were recorded each time the gas tank was filled and the computer was then reset. Here are the mpg values for a random sample of 20of these records:

15.813.615.619.122.415.622.517.219.422.6
19.418.014.618.721.014.822.621.514.320.9
Construct and interpret a 95% confidence interval for the mean fuel efficiency M for this vehicle.

You have measured the systolic blood pressure of an SRS of 25company employees. A 95%confidence interval for the mean systolic blood pressure for the employees of this company is (122,138). Which of the following statements gives a valid interpretation of this interval?

(a) 95%of the sample employees have systolic blood pressure between 122and138.

(b) 95%of the population of employees have systolic blood pressure between 122and138.

(c) If the procedure were repeated many times, 95%of the resulting confidence intervals would contain the population mean systolic blood pressure.

(d) The probability that the population mean blood pressure is between 122and138is 0.95.

(e) If the procedure were repeated many times, 95%of the sample means would be between122and138.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.