ZuoTi.Pro
Question

1) A study of 100 professors showed that the time they spent on the average in...

1) A study of 100 professors showed that the time they spent on the average in creating test questions was 20.0 minutes per question. The standard deviation of the population is 1. Which of the following is the 90% confidence interval for the average number of minutes it takes to create a test question?

a) (18.36, 21.64) B)(19.74, 20.26) c)(19.84, 20.16) D)(19.88, 20.12)

2)

1) A previous analysis of paper boxes showed that the standard deviation of their lengths is 13 millimeters. A pakcer wishes to find the 95% confidence interval for the average length of a box. How many boxes does he need to measure to be accurate within 3 millimeters?

2)A food snack manufacturer samples 7 bags of pretzels off the assembly line and weighs their contents. If the sample mean is 12.7 oz. and the sample standard deviation is 0.70 oz., find the 95% confidence interval 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

0 0
Add a comment
Know the answer?
Add Answer to:
1) A study of 100 professors showed that the time they spent on the average in...
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

  • 18) (6 pts) A study of 40 English composition professors showed that they spent, on average,...

    18) (6 pts) A study of 40 English composition professors showed that they spent, on average, 12.6 minutes correcting a student's term paper. (a) Find the 90% confident interval of the population mean u when S = 2.5 minutes. (b) If a professor stated that he spent, on average, 30 minutes correcting a term paper, what would be your reaction :)) ? 19) (5 pts) Find the Z-score that corresponds to the given area Shaded Area A-0.8907 20) (6 pts)...

  • A sample of 100 units showed a sample mean 12 oz with a standard deviation 3...

    A sample of 100 units showed a sample mean 12 oz with a standard deviation 3 oz. Obtain the 95% confidence interval for the population mean. Question options: [11.2 , 12.8] [11.4 , 12.6] [11.1 , 12.9] [11.6 , 12.6]

  • A recent study of 100 employees of city X showed that the mean of the distance...

    A recent study of 100 employees of city X showed that the mean of the distance they traveled to work was 35.75 km. The sample standard deviation was 5 km. Find the 95% confidence interval of the true mean.

  • Question 12 8 pts A study of 80 mice showed that their average weight was 6.8...

    Question 12 8 pts A study of 80 mice showed that their average weight was 6.8 ounces. The standard deviation of the population is 0.9 ounces. Which of the following is the 99% confidence interval for the mean weight per mouse? (5.4408, 8.7502) (6.0408,7.9502) (6.5408, 7.0592) (5.9408,8.1502) Question 13 8 pts 57 packages are randomly selected from packages received by a parcel service. The sample has a mean weight of 13,5 pounds; the population standard deviation for all packages is...

  • 7. In a sample of 100 boxes of a certain type, the average compressive strength was...

    7. In a sample of 100 boxes of a certain type, the average compressive strength was 6230 N, and the standard a. Find a 95% confidence interval for the mean com- b Find a 99% confidence interval for the mean com- c. An engineer claims that the mean strength is be- deviation was 221 N pressive strength of boxes of this type. pressive strength of boxes of this type. tween 6205 and 6255 N. With what level of confi dence...

  • A study of 65 bolts of carpet showed that their average length was 78.2 yards. The...

    A study of 65 bolts of carpet showed that their average length was 78.2 yards. The standard deviation of the population is 1.6 yards. Which of the following is the 80% confidence interval for the mean length per bolt of carpet?

  • A survey taken several years ago found that the average time a person spent reading the...

    A survey taken several years ago found that the average time a person spent reading the local daily newspaper was 10.8 minutes. The standard deviation of the population was 3 minutes. To see whether the average time had changed since the newspaper's format was revised, the newspaper editor surveyed 36 individuals. The average time that the 36 people spent reading the paper was 12.2 minutes.   (a) At α = 0.02, is there a change in the average time an individual...

  • A survey taken several years ago found that the average time a person spent reading the...

    A survey taken several years ago found that the average time a person spent reading the local daily newspaper was 10.8 minutes. The standard deviation of the population was 3 minutes. To see whether the average time had changed since the newspaper's format was revised, the newspaper editor surveyed 36 individuals. The average time that the 36 people spent reading the paper was 12.2 minutes.   (a) At α = 0.02, is there a change in the average time an individual...

  • A random sample of 144 checking accounts at a bank showed an average daily balance of...

    A random sample of 144 checking accounts at a bank showed an average daily balance of $295. The standard deviation of the population is known to be $72. Please answer the following questions: (a) Find the standard error of the mean. (b) Give a point estimate of the population mean. (c) Construct a 95% confidence interval estimates for the mean.

  • A study of 45 white mice showed that their average weight was 4.7 ounces. The standard...

    A study of 45 white mice showed that their average weight was 4.7 ounces. The standard deviation of the population is 0.7 ounces. Which of the following is the 80% confidence interval for the mean weight per white mouse?

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