Question

A random sample of 10 measurements on the breaking strength of a certain type of material...

A random sample of 10 measurements on the breaking strength of a certain type of material has a variance 3.21 psi2 . Repeated measurements on a second machine with 9 measurements shows a variance 2.32 psi2 . Assuming that the measurements are normally distributed, what is the ratio between the two variances at the 95% confidence level?

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
1. A certain change in a manufacturing process is being considered. Samples are taken from both...
1. A certain change in a manufacturing process is being considered. Samples are taken from both the existing and the new process to determine if the change will result in an improvement. If 110 of 1440 items from the existing process are found defective, and 78 of 1785 items from the new process are found defective. At 90% confidence level what would you conclude? 2. Estimate the variance of filling a cannery, for 10 cans were selected at random and...
Past experience has indicated that the breaking strength of yarn used in manufacturing drapery material is...
Past experience has indicated that the breaking strength of yarn used in manufacturing drapery material is normally distributed and that σ = 8.7 psi. A random sample of nine specimens is tested, and the average breaking strength is found to be 86.5 psi. The 95% confidence interval for the true mean breaking strength is written as (A ; B). Find the value of A? round your answer to three digits.
For a random sample of 50 measurements of the breaking strength of Brand A cotton threads,...
For a random sample of 50 measurements of the breaking strength of Brand A cotton threads, sample mean ¯x1 = 210 grams, sample standard deviation s1 = 8 grams. For Brand B, from a random sample of 50, sample mean ¯x2 = 200 grams and sample standard deviation s2 = 25 grams. Assume that population distributions are approximately normal with unequal variances. Answer the following questions 1 through 3. 1. What is the (estimated) standard error of difference between two...
5. The breaking strength (in lb/in) for a certain type of fabric has mean 104 and...
5. The breaking strength (in lb/in) for a certain type of fabric has mean 104 and standard deviation 15. A random sample of 100 pieces of fabric is drawn. a) What is the probability that the sample mean breaking strength is less than 100 lb/in? b) Find the 70th percentile of the sample mean breaking strength. c) How large a sample size is needed so that the probability is 0.05 that the sample mean is less than 100?  
Two types of plastics are suitable for use by an electronics component manufacturer. The breaking strength...
Two types of plastics are suitable for use by an electronics component manufacturer. The breaking strength of these plastics is very important. From a random sample size of n1=18, and n2=16, we obtained that X1-bar=151.2, S1=1.4 and X2-bar=152.3, S2=1.65. Calculate a 95% confidence interval on the ratio of variances. With 95% confidence, what is the left-value of the two-sided confidence interval on the ratio of variances? Your Answer:
Two types of plastics are suitable for use by an electronics component manufacturer. The breaking strength...
Two types of plastics are suitable for use by an electronics component manufacturer. The breaking strength of these plastics is very important. From a random sample size of n1=18, and n2=16, we obtained that X1-bar=151.2, S1=1.4 and X2-bar=152.3, S2=1.65. Calculate a 95% confidence interval on the ratio of variances. With 95% confidence, what is the right-value of the two-sided confidence interval on the ratio of variances? Your Answer:
Two types of plastics are suitable for use by an electronics component manufacturer. The breaking strength...
Two types of plastics are suitable for use by an electronics component manufacturer. The breaking strength of these plastics is very important. From a random sample size of n1=18, and n2=16, we obtained that X1-bar=151.2, S1=1.4 and X2-bar=152.3, S2=1.65. Calculate a 95% confidence interval on the difference in means, assuming that the population variances are equal. With 95% confidence, what is the left-value of the two-sided confidence interval on the difference in means? Your Answer:
Suppose the breaking strength of plastic bags is a Gaussian random variable. Bags from company 1...
Suppose the breaking strength of plastic bags is a Gaussian random variable. Bags from company 1 have a mean strength of 8 kilograms and a variance of 1 kg2 ; Bags from company 2 have a mean strength of 9 kilograms and a variance of 0.5 kg2 . Assume we check the sample mean ?̅ 10 of the breaking strength of 10 bags, and use ?̅ 10 to determine whether a batch of bags comes from company 1 (null hypothesis...
Exercise 1. The sound intensity of a certain type of food processor in normally distributed with...
Exercise 1. The sound intensity of a certain type of food processor in normally distributed with standard deviation of 2.9 decibels. If the measurements of the sound intensity of a random sample of 9 such food processors showed a sample mean of 50.3 decibels, find a 95% confidence interval estimate of the (true, unknown) mean sound intensity of all food processors of this type. Exercise 2. What is the answer to Exercise 1 if the standard deviation of the population...
1.14. A random sample of 22 shearing pins is taken in a study of the Rockwell...
1.14. A random sample of 22 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 22, yielding an average value of 58.50 with a sample standard deviation of 15.5. Assuming the measurements are normally distributed. Construct a 95% two-sided confidence interval for the mean Rockwell hardness. (2 Points) If true standard deviation is equal to 12, how large a sample size is necessary...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT