ZuoTi.Pro
Question

9.2 An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 40 hours. If a sample of 30 bulbs has an average life of 780 hours, find a 96% confidence interval for the population mean of all bulbs produced by this firm.
Many cardiac patients wear an implanted pace- maker to control their heartbeat. A plastic connec- tor module mounts on the top of the pacemaker. As- suming a standard deviation of 0.0015 inch and an ap- proximately normal distribution, find a 95% confidence
9.5 A random sample of 100 automobile owners in the state of Virginia shows that an automobile is driven on average 23,500 kilometers per year with a standard de- viation of 3900 kilometers. Assume the distribution of measurements to be approximately normal (a) Construct a 99% confidence interval for the aver- age number of kilometers an automobile is driven annually in Virginia (b) What can we assert with 99% confidence about the possible size of our error if we estimate the aver- age number of kilometers driven by car owners in Virginia to be 23,500 kilometers per year?
9.6 How large a sample is needed in Exercise 9.2 if we wish to be 96% confident that our sample mean will be within 10 hours of the true mean?
math   Statistics-And-Probability   
0 0
Add a comment Improve this question Transcribed image text
Next > < Previous
Sort answers by oldest

Homework Answers

Answer #1

Gfven hat, ไม่ Pon the given frfsmatfor Samp le siae, n-30 zle mean o a speclHed amount e uhen the sample tze is 096 098 ue ID

0 3
Add a comment
Know the answer?
Add Answer to:
9.2 An electrical firm manufactures light bulbs that have a length of life that is approximately...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions

  • 9.5 A random sample of 100 automobile owners in the state of Virginia shows that an...

    9.5 A random sample of 100 automobile owners in the state of Virginia shows that an automobile is driven on average 23,500 kilometers per year with a standard de- viation of 3900 kilometers. Assume the distribution of measurements to be approximately normal. (a) Construct a 99% confidence interval for the aver- age number of kilometers an automobile is driven annually in Virginia. • (b) What can we assert with 99% confidence about the possible size of our error if we...

  • An electrical firm manufactures light bulbs that have a length of life that is approximately normally...

    An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 40 hours. If a sample of 30 bulbs has an average life of 780 hours, find a 96% confidence interval for the population mean of all bulbs produced by this firm. How large a sample is needed if we wish to be 96% confident that our sample mean will be within 10 hours of the true mean?

  • An electrical firm manufactures light bulbs that have a length of life that is approximately normally...

    An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 25 hours. If we wish to be 99% confident that the sample mean will be within 4 hours of the true mean, how large a sample is needed? At least observations.

  • An electrical firm manufactures light bulbs that have a length of life that is approximately norm...

    An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 20 hours.  If a sample of 30 bulbs has an average life of 780 hours, how large a sample is needed if we wish to be 95% confident that our sample mean will be within 4 hours of the true mean. a. 62 b. 68 c. 100 d. 97

  • An electrical firm manufactures light bulbs that have a length of life that is approximately normally...

    An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 20 hours.  If a sample of 30 bulbs has an average life of 780 hours, how large a sample is needed if we wish to be 95% confident that our sample mean will be within 4 hours of the true mean. a. 62 b. 68 c. 100 d. 97

  • A n electrical firm manufactures light bulbs that have a length of life that is approximately...

    A n electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a sample standard deviation of 40 hours.  If a sample of 16 bulbs has an average life of 770 hours, find a 95% two-sided confidence interval for the population mean of all bulbs produced by this firm. a. 750.40 < µ < 789.60 b. 752.47 < µ < 787.53 c. 761.47 < µ < 796.53 d. 748.69 < µ < 791.31

  • An electrical firm manufactures light bulbs that have a length life with normal distribution, and a...

    An electrical firm manufactures light bulbs that have a length life with normal distribution, and a standard deviation of o = 40 hours. A sample of size n = 100 bulbs has an average life of 650 hours. Find the lower 99% confidence bound for the population mean of all bulbs produced by this firm. (use interval notation). What z value (s) did you use to calculate the confidence interval above? Explain why briefly.

  • An electrical firm manufactures light bulbs that have a length life with normal distribution, and a...

    An electrical firm manufactures light bulbs that have a length life with normal distribution, and a standard deviation of o = 40 hours. A sample of size n = 100 bulbs has an average life of 740 hours. Find the 95% confidence interval for the population mean of all bulbs produced by this firm. (use interval notation). What z value(s) did you use to calculate the confidence interval above? Explain why briefly.

  • Please explain the Z values used. An electrical firm manufactures light bulbs that have a length...

    Please explain the Z values used. An electrical firm manufactures light bulbs that have a length life with normal distribution, and a standard deviation of o = 40 hours. A sample of size n = 100 bulbs has an average life of 650 hours. Find the lower 99% confidence bound for the population mean of all bulbs produced by this firm. (use interval notation). What z value(s) did you use to calculate the confidence interval above? Explain why briefly.

  • An electrical firm manufactures light bulbs that have a length life with normal distribution, and a...

    An electrical firm manufactures light bulbs that have a length life with normal distribution, and a standard deviation of o = 10 hours. A sample of size n = 100 is obtained, and its sample mean is calculated to be I = 320 hours. Find the 95% confidence interval for the average length life p. Find the upper 95% bound for the average length life u. Find the lower 95% bound for the average length life u. Give your answer...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT