Question

A random sample of 20 houses selected from a city showed that the mean size of...

A random sample of 20 houses selected from a city showed that the mean size of these houses is 1850 square feet with a standard deviation of 320 square feet. Assume that the sizes of all houses in this city have an approximate normal distribution. The 95% confidence interval for the variance of all house sizes in this city is:
Math   Statistics-And-Probability   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

Chi square critical values at 0.05 significance level with 19 df = 8.9065 , 32.8523

95% confidence interval for is

( n - 1) S2 / U < < ( n - 1) S2 / L

19 * 3202 / 32.8523 < < 19 * 3202 / 8.9065

59222.64 < < 218447.20

95% CI is ( 59222.64 , 218447.20 )

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
4. A random sample of 8 houses in Scranton yields an average size of 1,966 square...
4. A random sample of 8 houses in Scranton yields an average size of 1,966 square feet. The standard deviation for the size of all houses in Scranton is found to be 355 square feet. Assuming that the sizes of all houses in the city have an approximately normal distribution, find a 95% confidence interval for the average size of all houses in Scranton. Conclusion: We can be __________confident that the mean size of all houses in Scranton is between...
A random sample of size 30 is selected from a known population with a mean of...
A random sample of size 30 is selected from a known population with a mean of 13.2 and a standard deviation of 2.1. Samples of the same size are repeatedly collected, allowing a sampling distribution of sample means to be drawn. a. What is the expected shape of the resulting distribution? b. Where is the sampling distribution of sample means centered? c. What is the approximate standard deviation of the sample means? 2. The lifetimes of a certain type of...
A random sample of 226 houses in Hays were appraised. The mean value of the sample...
A random sample of 226 houses in Hays were appraised. The mean value of the sample of houses was $83,510, with a standard deviation of $26,625. What would be the 95% confidence interval for the mean value of all houses in Hays? $82,900 to $84,730 $81,790 to $85,920 $80,031 to $86,989 $79,550 to 87,470
A random sample of house sizes in a major city has a sample mean of 1204.9...
A random sample of house sizes in a major city has a sample mean of 1204.9 sq ft and a standard deviation of 124.6 sq ft. Use the Empirical Rule to determine the approximate percentage of house size that lies between 955.7 sq ft and 1454.1 sq ft. For full credit sketch the empirical rule.
A random sample of size 16 valves from a normal population showed a mean of 53...
A random sample of size 16 valves from a normal population showed a mean of 53 and a sum of squares of deviation from the mean equals to 150. Obtain 95% confidence limits of the mean of population.
A random sample of 20 purchases showed the amounts in the table​ (in $). The mean...
A random sample of 20 purchases showed the amounts in the table​ (in $). The mean is ​$49.64 and the standard deviation is ​$23.80. ​a) Construct a 98​% confidence interval for the mean purchases of all​ customers, assuming that the assumptions and conditions for the confidence interval have been met. ​b) How large is the margin of​ error? ​c) How would the confidence interval change if you had assumed that the standard deviation was known to be ​$24​?
A random sample of 20 purchases showed the amounts in the table (in $). The mean...
A random sample of 20 purchases showed the amounts in the table (in $). The mean is $49.88 and the standard deviation is $20.86. a) Construct a 80% confidence interval for the mean purchases of all customers, assuming that the assumptions and conditions for the confidence interval have been met. b) How large is the margin of error? c) How would the confidence interval change if you had assumed that the standard deviation was known to be $21?
The living spaces of all homes in a city have a mean of 2500 square feet...
The living spaces of all homes in a city have a mean of 2500 square feet and a standard deviation of 360 square feet. Let x¯ be the mean living space for a random sample of 20 homes selected from this city. Find the mean of the sampling distribution of x¯. Enter an exact answer. mean of x¯= square feet Find the standard deviation of the sampling distribution of x¯. Round your answer to one decimal place. standard deviation of...
4. A pediatrician’s records showed the mean height of a random sample of 25 girls aged...
4. A pediatrician’s records showed the mean height of a random sample of 25 girls aged 12 months to be 29.53 inches with a standard deviation of 1.0953 inches. a. Construct a 95% confidence interval for the true mean height. b. What sample size would be needed for 95 percent confidence and an error of +/- .20 inches?
A random sample of 500 owners of single-family homes is drawn from the population of a...
A random sample of 500 owners of single-family homes is drawn from the population of a city. Let the random variable X denote the value of the house, in thousands of dollars. The following information is given to you: n=500, ∑xi =107,226 ∑ (xi − x )2 =1,398,308 a. Compute the sample mean and standard deviation of the value of the houses in this sample. b. Construct a 95% confidence interval for the mean value of the houses in this...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT