Reference no: EM131062656
Confidence Intervals and Sample Size-
1. A study of 40 bowlers showed that their average score was 186. The standard deviation of the population is 6.
(a) Construct a 95% confidence interval for the mean score of all bowlers.
(b) Construct a 95% confidence interval for the mean score of all bowlers if a sample of size 100 is used instead of 40.
(c) Explain why one confidence interval is larger than the other.
2. A health care professional wishes to estimate the birth weights of infants. How large a sample must she select if she desires to be 90% confident that the true mean is within 6 ounces of the sample mean? The standard deviation is estimated to be 8 ounces.
3. A random sample of 78 students were interviewed and 59 said they would vote for Jennifer McNamara as student body president. Let p represent the proportion of all students who will vote for Jennifer. Find a 90% confidence interval for p.
4. As part of an Environmental Studies class project students measured the circumference of a random sample of 45 Blue Spruce trees near Brainard Lake, Colorado. The sample mean circumference was 29.8 inches. Assume that σ is known to be 7.2 inches. Find a 95% confidence interval for the population mean circumference of all Blue Spruce trees near this lake.
5. A random sample of 56 credit card holders showed that 41 regularly paid their credit card bills on time. Find a 95% confidence interval for the proportion of all people who regularly paid their credit card bill on time.
6. A researcher wants to know what percentage of males athletes wear contact lenses during performances. Let p represent the proportion of males athletes who wear contact lenses. If there is no preliminary estimate for p, how many male athletes should be included in a random sample to be 90% sure that a point estimate for p will be within a distance of 0.05 from p.
7. A sample of 25 novels has a standard deviation of 9 pages. Find the 95% confidence interval of the population standard deviation.
|
Glass ceiling exists today for women
: Do you believe the glass ceiling exists today for women? Give me some examples. Go to the internet and find data or anecdotal stories there with regard to the glass ceiling.
|
|
What security concerns are associated with the thumb drive
: What security concerns are associated with the thumb drive - How could information security policies or information security plans help the cafe in this type of situation?
|
|
Role of social media influence
: Discuss the role of social media's influence (Twitter, Facebook, and YouTube) in activism and revolution on the world stage.
|
|
Represent a minority group in the military
: Women represent a minority group in the military. Men are in the minority as nurses and paralegals.
|
|
Confidence interval for the mean score of all bowlers
: A study of 40 bowlers showed that their average score was 186. The standard deviation of the population is 6. Construct a 95% confidence interval for the mean score of all bowlers
|
|
Discuss hypotheses-data collection methods
: In addition, discuss hypotheses, data collection methods, data analysis methods, and the role of variables in your PowerPoint presentation.
|
|
Concepts of class-poverty-ethnicity
: Analyse the statement, ' Mental illness is a social problem' . To examine this question draw on one or two of the concepts of class, poverty, ethnicity, gender or race.
|
|
What do think should be criteria for labeling product green
: Because "being green" has become so popular, some organizations reference their green initiatives in their marketing materials to give the impression that their policies or products are environmentally friendly when, really, they are simply follow..
|
|
Identify a specific international company
: Evaluate these issues and determine how they affect our business - Identify and analyze three causes for its globalization
|