Question

2. A machine produces bolts with an average length of 16 inches. A manager selects a...

2. A machine produces bolts with an average length of 16 inches. A manager selects a sample of 25 bolts. The average length in the sample was 15.95 inches with a variance of 0.4 inches. The acceptable variance for the length is 0.3 inches. (Note that 1 inch is equivalent to 2.54 cm). a. Construct a 95% confidence interval for the population variance. b. State the null and alternative hypotheses to test whether or not the population variance equals 0.3 inches. c. Compute the test statistic.

Math   Statistics-And-Probability   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

0 0
Know the answer?
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
Similar Questions
A machine is required to produce bolts with an average length of 2.00 cm. A random...
A machine is required to produce bolts with an average length of 2.00 cm. A random sample of 120 bolts had a mean length of 1.991 cm and a standard deviation of 0.766 cm. (a) [7] Does the sample provide sufficient evidence that the machine is not operating properly? Test an appropriate hypothesis at α = 0.01. (b) [5] Make a 99% confidence interval for the average length. What additional information does it provide over the test in (a)? (c)...
A bolt manufacturer wants to investigate the machine that produces bolts with a diameter of 0.18...
A bolt manufacturer wants to investigate the machine that produces bolts with a diameter of 0.18 centimeters. If the variance of the diameters is equal to 0.015, then the machine is working as expected. A random sample of 26 bolts has a standard deviation of 0.1806. Does the manufacturer have evidence at the α=0.1 level that the variance of the bolt diameters is more than required? Assume the population is normally distributed. Step 1 of 5: State the null and...
A bolt manufacturer wants to investigate the machine that produces bolts with a diameter of 0.23...
A bolt manufacturer wants to investigate the machine that produces bolts with a diameter of 0.23 centimeters. If the variance of the diameters is equal to 0.025. then the machine is working as expected. A random sample of 26 bolts has a standard deviation of 0.2318. Does the manufacturer have evidence at the α=0.1 level that the variance of the bolt diameters is more than required? Assume the population is normally distributed Step 1 of 5: State the null and...
An automatic CNC machine produces bolts which are stamped out of a length of metal. Various...
An automatic CNC machine produces bolts which are stamped out of a length of metal. Various faults may generally occur during the production process, such as, the heads or the threads may be incorrectly formed, the length might be incorrect, and so on. Assuming that 4 bolts out of every 100 produced are defective in some way. If a sample of 50 bolts is drawn at random, then the manufacturer might be satisfied that his defect rate is still 4%...
Lazurus Steel Corporation produces iron rods that are supposed to be 36 inches long. The machine...
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...
Lazurus Steel Corporation produces iron rods that are supposed to be 36 inches long. The machine...
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...
steel factory produces iron rods that are supposed to be 36 inches long. The machine that...
steel factory 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 these rods vary slightly. It is known that when the machine is working properly, the mean length of the rods is 36 inches. According to design, the standard deviation of the lengths of all rods produced on this machine is always equal to .05 inches. The quality control department...
A bolt manufacturer is trying to calibrate a new machine that is to produce 0.23cm0.23⁢cm bolts....
A bolt manufacturer is trying to calibrate a new machine that is to produce 0.23cm0.23⁢cm bolts. The manufacturer takes a random sample of 2929 bolts produced by the new machine and finds that the standard deviation is 0.13350.1335. If the machine is operating properly, the variance of the diameters of the bolts should be 0.0150.015. Does the manufacturer have evidence at the α=0.01α=0.01 level that the variance of the bolt diameters is more than required? Assume the population is normally...
A machine produces metal rods with an average length of 100 cm. A quality control carried...
A machine produces metal rods with an average length of 100 cm. A quality control carried out on one of 80 stems allowed to calculate an average length of 99.5 cm and a standard deviation of 1 cm. We want to establish whether the machine needs to be adjusted: with a significance level of 2%, we do a hypothesis test to determine whether the length of the rods produced by the machine is different from 100 cm. a) State the...
Suppose that, in a population of middle-aged men, the average length of a male's forearm is...
Suppose that, in a population of middle-aged men, the average length of a male's forearm is 15 inches, with a standard deviation of 1.5 inches. However, we have reason to believe that this figure is false. So, we test a sample of 49 men and find that within this sample, we observe a mean of 16 inches. a) Estimate a mean forearm length. b) Conduct a hypothesis test with a null and alternative hypothesis.
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT