Elementary Statistics
3rd Edition
ISBN: 9781260373561
Author: Navidi, William
Publisher: MCGRAW-HILL HIGHER EDUCATION
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Textbook Question
Chapter 8.2, Problem 25E
Hip surgery: In a sample of 123 hip surgeries of a certain type, the average surgery time was 136.9 minutes with a standard deviation of 22.6 minutes.
- Construct a 95% confidence interval for the
mean surgery time for this procedure. - If a 99% confidence interval were constructed with these data, would it be wider or narrower than the interval constructed in part (a)? Explain.
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Chapter 8 Solutions
Elementary Statistics
Ch. 8.1 - In Exercises 17—20, fill in each blank with the...Ch. 8.1 - Prob. 18ECh. 8.1 - In Exercises 17—20, fill in each blank with the...Ch. 8.1 - In Exercises 17-20, fill in each blank with the...Ch. 8.1 - In Exercises 21-24, determine whether the...Ch. 8.1 - In Exercises 21-24, determine whether the...Ch. 8.1 - In Exercises 21-24, determine whether the...Ch. 8.1 - Prob. 24ECh. 8.1 - In Exercises 25-28, find the critical value z/2...Ch. 8.1 - In Exercises 25-28, find the critical value z/2...
Ch. 8.1 - In Exercises 25-28, find the critical value z/2...Ch. 8.1 - Prob. 28ECh. 8.1 - In Exercises 29-32, find the levels of the...Ch. 8.1 - In Exercises 29-32, find the levels of the...Ch. 8.1 - In Exercises 29-32, find the levels of the...Ch. 8.1 - In Exercises 29-32, find the levels of the...Ch. 8.1 - A sample of size n=49 is drawn from a population...Ch. 8.1 - Prob. 34ECh. 8.1 - A sample of size n=32 is drawn from a population...Ch. 8.1 - A sample of size n=64 is drawn from a population...Ch. 8.1 - A sample of sue n=10 is drawn from a normal...Ch. 8.1 - Prob. 38ECh. 8.1 - A population has standard deviation 21.3. How...Ch. 8.1 - Prob. 40ECh. 8.1 - A population has standard deviation =12.7 How...Ch. 8.1 - Prob. 42ECh. 8.1 - SAT scores: A college admissions officer takes a...Ch. 8.1 - Prob. 44ECh. 8.1 - Babies: According to the National Health...Ch. 8.1 - Watch your cholesterol: A sample of 314 patients...Ch. 8.1 - How smart is your phone? A random sample of 11...Ch. 8.1 - Stock prices: The Standard and Poors (S=50....Ch. 8.1 - High energy: A random sample of energy drinks had...Ch. 8.1 - Lets shake on it: A random sample of 12-ounce...Ch. 8.1 - Lifetime of electronics: In a simple random sample...Ch. 8.1 - Efficient manufacturing: Efficiency experts study...Ch. 8.1 - Prob. 53ECh. 8.1 - Prob. 54ECh. 8.1 - Prob. 55ECh. 8.1 - Prob. 56ECh. 8.1 - Prob. 57ECh. 8.1 - Prob. 58ECh. 8.1 - Which interval is which? Sam constructed three...Ch. 8.1 - Prob. 60ECh. 8.1 - Prob. 61ECh. 8.1 - Dont construct a confidence interval: A college...Ch. 8.1 - Interpret a confidence interval: A dean at a...Ch. 8.1 - Interpret a confidence interval: A survey...Ch. 8.1 - Interpret calculator display: The number of words...Ch. 8.1 - Prob. 66ECh. 8.1 - Prob. 67ECh. 8.1 - Prob. 68ECh. 8.1 - Prob. 69ECh. 8.1 - Prob. 70ECh. 8.2 - In Exercises 7 and 8, fill in each blank with the...Ch. 8.2 - Prob. 8ECh. 8.2 - Prob. 9ECh. 8.2 - Prob. 10ECh. 8.2 - Find the critical value t/2 needed to construct a...Ch. 8.2 - Find the critical value t/2 needed to construct a...Ch. 8.2 - A sample of size n=22 is drawn from a normal...Ch. 8.2 - A sample of size n=12 is drawn from a normal...Ch. 8.2 - A sample of size n=12 is drawn. Find the critical...Ch. 8.2 - A sample of size n=15 has sample mean x=2.1 and...Ch. 8.2 - A sample of size n=44 has sample mean x=56.9 and...Ch. 8.2 - A sample of size n=89 has sample mean x=87.2 and...Ch. 8.2 - A sample of size n=35 has sample mean x=34.85 and...Ch. 8.2 - Online courses: A sample of 263 students who were...Ch. 8.2 - Get an education: The General Social Survey asked...Ch. 8.2 - Fake Twitter followers: Many celebrities and...Ch. 8.2 - Lets go to the movies: A random sample of 35...Ch. 8.2 - Hip surgery: In a sample of 123 hip surgeries of a...Ch. 8.2 - Sound it out: Phonics is an instructional method...Ch. 8.2 - Software instruction: A hybrid course is one that...Ch. 8.2 - Baby talk: In a sample of 77 children, the mean...Ch. 8.2 - Baby weights: Following are weights: m pounds: of...Ch. 8.2 - Prob. 30ECh. 8.2 - Eat your spinach: Six measurements were made of...Ch. 8.2 - Mortgage rates: Following are interest rates...Ch. 8.2 - Hi-def: Following are prices of a random sample of...Ch. 8.2 - Big salary for the boss: Following is the total...Ch. 8.2 - Prob. 35ECh. 8.2 - Prob. 36ECh. 8.2 - Eat your kale: Kale is a type of cabbage commonly...Ch. 8.2 - Prob. 38ECh. 8.2 - Prob. 39ECh. 8.2 - Prob. 40ECh. 8.2 - Dont construct a confidence interval: There have...Ch. 8.2 - Dont construct a confidence interval: As of July...Ch. 8.2 - Prob. 43ECh. 8.2 - Prob. 44ECh. 8.2 - Prob. 45ECh. 8.2 - Prob. 46ECh. 8.2 - Prob. 47ECh. 8.3 - In Exercises 7 and 8, fill in each blank with the...Ch. 8.3 - In Exercises 7 and 8, fill in each blank with the...Ch. 8.3 - In Exercises 9 and 10, determine whether the...Ch. 8.3 - Prob. 10ECh. 8.3 - Prob. 11ECh. 8.3 - In Exercises 11-14, find the point estimate, the...Ch. 8.3 - In Exercises 11-14, find the point estimate, the...Ch. 8.3 - In Exercises 11-14, find the point estimate, the...Ch. 8.3 - In Exercises 15-18, use the given data to...Ch. 8.3 - In Exercises 15-18, use the given data to...Ch. 8.3 - In Exercises 15-18, use the given data to...Ch. 8.3 - In Exercises 15-18, use the given data to...Ch. 8.3 - Smart phone: Among 238 cell phone owners aged...Ch. 8.3 - Working at home: According to the U.S. Census...Ch. 8.3 - Sleep apnea: Sleep apnea is a disorder in which...Ch. 8.3 - Internet service: An Internet service provider...Ch. 8.3 - Volunteering: The General Social Survey asked 1294...Ch. 8.3 - SAT scores: A college admissions officer sampled...Ch. 8.3 - LOL: In the computer game League of Legends. some...Ch. 8.3 - Prob. 26ECh. 8.3 - Call me: A sociologist wants to construct a 95%...Ch. 8.3 - Reading proficiency: An educator wants to...Ch. 8.3 - Surgical complications: A medical researcher wants...Ch. 8.3 - Hows the economy? A pollster wants to construct a...Ch. 8.3 - Changing jobs: A sociologist sampled 200 people...Ch. 8.3 - Prob. 32ECh. 8.3 - Prob. 33ECh. 8.3 - Prob. 34ECh. 8.3 - Interpret calculator display: A sample of voters...Ch. 8.3 - Prob. 36ECh. 8.3 - Prob. 37ECh. 8.3 - Prob. 38ECh. 8.3 - Prob. 39ECh. 8.3 - Dont construct a confidence interval: At the end...Ch. 8.3 - Prob. 41ECh. 8.3 - Prob. 42ECh. 8.3 - Wilsons interval: The small-sample method for...Ch. 8.4 - In Exercises 5 and 6, fill in each blank with the...Ch. 8.4 - In Exercises 5 and 6, fill in each blank with the...Ch. 8.4 - In Exercises 7 and 8, determine whether the...Ch. 8.4 - Prob. 8ECh. 8.4 - Find the critical values for a 95% confidence...Ch. 8.4 - Find the critical values for a 99% confidence...Ch. 8.4 - Construct a 95% confidence interval for the...Ch. 8.4 - Construct a 99% confidence interval for the...Ch. 8.4 - SAT scores: Scores on the math SAT are normally...Ch. 8.4 - IQ scores: Scores on an IQ test are normally...Ch. 8.4 - Baby weights: are weights of 12 two-month-old baby...Ch. 8.4 - Eat your cereal: Boxes of cereal are labeled as...Ch. 8.4 - Eat your spinach: Six measurements were made of...Ch. 8.4 - Prob. 18ECh. 8.4 - Prob. 19ECh. 8.4 - Using the normal approximation: Refer to Exercise...Ch. 8.4 - Prob. 21ECh. 8.4 - More accuracy: Refer to Exercise 19. Use the more...Ch. 8.4 - Prob. 23ECh. 8.5 - In Exercises 5-12, state which type of parameter...Ch. 8.5 - In Exercises 5-12, state which type of parameter...Ch. 8.5 - In Exercises 5-12, state which type of parameter...Ch. 8.5 - Prob. 8ECh. 8.5 - In Exercises 5-12, state which type of parameter...Ch. 8.5 - In Exercises 5-12, state which type of parameter...Ch. 8.5 - In Exercises 5-12, state which type of parameter...Ch. 8.5 - In Exercises 5-12, state which type of parameter...Ch. 8.5 - Prob. 13ECh. 8.5 - Ages of students: A simple random sample of 100...Ch. 8.5 - Calories in bread: Following are the numbers of...Ch. 8.5 - Credit card debt: In a survey of 1118 U.S. adults...Ch. 8.5 - Windy place: Mt. Washington, New Hampshire, is one...Ch. 8.5 - An apple a day: Following are the numbers of grams...Ch. 8.5 - Pneumonia: In a simple random sample of 1500...Ch. 8.5 - Prob. 20ECh. 8 - Define the following terms: Point estimate...Ch. 8 - Prob. 2CQCh. 8 - Prob. 3CQCh. 8 - Construct a confidence interval for the population...Ch. 8 - Prob. 5CQCh. 8 - Prob. 6CQCh. 8 - Prob. 7CQCh. 8 - Prob. 8CQCh. 8 - Prob. 9CQCh. 8 - Prob. 10CQCh. 8 - Prob. 11CQCh. 8 - Prob. 12CQCh. 8 - Prob. 13CQCh. 8 - Prob. 14CQCh. 8 - Prob. 15CQCh. 8 - Prob. 1RECh. 8 - Prob. 2RECh. 8 - Cost of environmental restoration: In a survey of...Ch. 8 - Prob. 4RECh. 8 - Prob. 5RECh. 8 - Contaminated water: Polychlorinated biphenyls...Ch. 8 - Prob. 7RECh. 8 - Cost of repairs: A sample of eight repair records...Ch. 8 - Cost of repairs: Refer to Exercise 8. Assume the...Ch. 8 - Prob. 10RECh. 8 - Prob. 11RECh. 8 - Sleep time: In a sample of 87 young adults, the...Ch. 8 - Leaking tanks: Leakage from underground fuel tanks...Ch. 8 - Prob. 14RECh. 8 - Prob. 15RECh. 8 - Prob. 1WAICh. 8 - What factors can you think of that may affect the...Ch. 8 - Prob. 3WAICh. 8 - Prob. 4WAICh. 8 - Prob. 5WAICh. 8 - When constructing a confidence interval for , how...Ch. 8 - Prob. 7WAICh. 8 - Prob. 1CSCh. 8 - Prob. 2CSCh. 8 - Prob. 3CSCh. 8 - Prob. 4CSCh. 8 - Prob. 5CS
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