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Confidence Interval

Assistance with Case Study

I am a graduate student, needing assistance with a case study that I am working on. Due to scheduling issues and an increased work load this week, I am needing help with some of the leg work required. I will attach all files needed and will GUARANTEE proper citation/referencing of any assistance you may provide. Given the qu

Need help with excel formulas

43. A phoenix wealth management/harris interactive survey of 1500 individuals with net worth of $1 million or more provided a variety of statistics on wealthy people. The previous three-year period has been bad for the stock market, which motivated some of the questions asked. a. The survey reported that 53% of the re

Confidence Interval Estimate for the Mean

Question 1 Sample with size n = 100 has mean = 30. Assuming the population standard deviation is 8, construct 95% confidence interval for population mean. Use formula on page 312, z?/2 = 1.96 Answer between 28.4 and 31.6 between 27.0 and 33.0 between 26.1 and 34.2

Confidence Interval and Margin of Error

In an effort to estimate the mean amount spent per customer for dinner at a major Atlanta restaurant, data were collected for a sample of 49 customers. Assume a population standard deviation of $5. a. At 95% confidence, what is the margin of error? b. If the sample mean is $24.80, what is the 95% confidence interval for th

Sample Size & Confidence Interval

1. The library New York City Public Library asked assistant interval estimate number books checked day. The assistant a sample found 880 books. The librarian interval estimate 790 970 books checked day. Which efficient unbiased point estimate number books checked day New York City Public Library is? 2. A researcher dean wou

Confidence Intervals and Sample Size Problems

1) Eight chemical elements do not have isotopes (different forms of the same element having the same atomic number but different atomic weights). A random sample of 30 of the elements that do have isotopes showed a mean number of 19.63 isotopes per element and the population a standard deviation of 18.73. Estimate the true

MBA statistics-Confidence Interval Estimate

Difficult to comprehend. Many need to be in Excel format to answer. 1. What proportion of Americans get most of their news from the internet? According to a poll conducted by Pew Research Center, 40% get most of their news from the Internet. a. To conduct a follow-up study that would provide 95% confidence that the point es

MBA statistics-Confidence Interval Estimate

Difficult for me to comprehend! Several need to be answered with Excel. 1. If sample mean = 85, and n=64, construct a 95% confidence interval estimate for the population mean, mu. 2.The manager of a paint supply store wants to estimate the actual amount of paint contained in 1-gallon cans purchased from a nationally known

Quantative Analysis

A corporation owns several companies. The strategic planner for the corporation believes dollars spent on advertising can to some extent be a predictor of total sales dollars. As an aid in long-term planning, she gathers the followings sales and advertising information from several of the companies for 2002 ($ millions). Adve

Use of stratified random sampling; statistical control

1. When is it appropriate to use stratified random sampling. 2. What is meant when we say that a process is in statistical control? 3. Discuss ratio, interval, nominal and ordinal variables. 4. Explain what is meant by a margin of error for a confidence interval.

Statistics: Confidence Interval problems

See attached data file. #1. 8.15: Using Table A.4 (page 640), find t.100, t.025, and t.001 based on 11 degrees of freedom. Also, find these t points based on 6 degrees of freedom. #2. 8.16: Suppose that for a sample of n = 11 measurements, we find that _ = 72 and s 5. Assuming normality, compute confidence intervals

Testing Procedure, p-Value and Confidence Interval

The mean + sd of In [calcium intake (mg)] among 25 females, 12 to 14 years of age, below the poverty level is 6.56 + 0.64. Similarly, the mean + 1 sd of In [calcium intake (mg)]among 40 females, 12 to 14 years of age, above the poverty level is 6.80 + 0.76. 8.3) What is the appropriate procedure to test for a significant diff

Confidence interval to test proportion of US households with a dog

A humane society claims that less than 35% of U.S. households own a dog. In a random sample of 400 U.S. households, 156 say they own a dog. (5) Describe the population of interest and calculate the numerical value of the statistic p Ì? that that we will use to estimate the population proportion p. (5) Construct a 95% c

Interval Estimation & Margin of Error

# 1. use the sample data and confidence level to construct the confidence interval estimate of the population proportion p. n= 550, x= 440, 95% confidence < p < #2 use the given confidence level and sample data to find (a) the margin of error and (b) the confidence interval for the population mean m. assume that t

Confidence Interval, Normal Probability & Hypothesis Testing

#4. you collected the following information: n=38 x bar= 12.35 s=3.82 find the 95% confidence interval estimate for m- mule #2. heavy duty light bulbs made by a certain company claim to have lives that are normally distributed with a mean of 5000 hours and a standard deviation of 400 hours. A. find the pr

Management Science

The number of staff personnel needed to handle patients at a medical center is determined by the mean time that patients must wait before being attended to by a physician. For a random sample of 100 previously recorded emergencies, the sample mean waiting time was 72 minutes, with a standard deviation of 28 minutes. a. wh


Need help on the following problems (1) Freshman 15 Weight gains. (Attached Data set 3) Based on the sample results, find the best point estimate of the percentage of college students who gain weight in their freshman year. a. Construct a 95% confidence interval estimate of the percentage of college students who gain wei

Confidence Interval Concepts

How is the confidence level determined? Who in your workplace might set this level? Should companies use the same confidence interval each time a confidence interval is determined or should the level change based on situations? If it changes based on situations, what type of situations might call for higher confidence levels?

Confidence interval for mean

a random sample of 50 engineers of a large technology company that the sample mean is 34.4 year. assume that the population standard deviation is 8 years. construct and explain a 98% confidence interval estimate of the average age of all engineers employed by the company.

confidence interval for the mean

2) Constructing a confidence interval for the mean. M&M Candies Use the following data of the weight in grams of M&M plain candies. Assume the population is normally distributed. **Hint: copy and paste the data into excel. Then use excel to find the sample mean and sample standard deviation you will need to complete the fo

Confidence Interval for Mean Difference.

1. 12 mature citrus trees of one variety and 15 of another gave means and standard deviations of their heights as 13.8 and 12.9 ft (means), and 1.2 and 1.5 ft (standard deviations). Find a 95% confidence interval for the true difference in average heights between all trees of the first and the second variety. Would you be able

Confidence Interval and Sample Size Calculations

1. Of 300 people waiting lunch at a department store cafeteria, 102 had dessert. What is the confidence associated with a Rao score interval of length .1 (i.e., margin of error .05)? 2. Calculate the sample size necessary to estimate the proportion of drivers that exceed the spend limit on a stretch of a road between Bakersfi

Hypothesis Testing & Confidence Interval for Mean

Children's scores on a measure of aggression are known to have a normal distribution, with a mean of 50 and a standard deviation of 6. A researcher takes a random sample of 49 children, has them listen to calming music for 4 hours, and then measures the aggression level of this sample of children. The sample has a mean of 51.

Descriptive Statistics & Confidence Interval

Please see attached files. 1. The figure below shows the probability histogram for the total number of spots when a die is rolled eight times. The shaded area represents the chance that the total will be between__ _ and ___ (inclusive). 8. A coin is tossed 100 times. True or false, and explain: (a) The expected value fo

Confidence Interval Explanation

1) To aid in planning the development of a tourist shopping area, a state agency wants to estimate the average dollar amount spent by a tourist in an existing shopping area. A simple random sample of 56 tourists gave an average of $258 with standard deviation of $85. a) Give a 95% confidence interval for the average of the p

Identify outcome of the following Polls.

POLL: OBAMA, MCCAIN LEAD IN N.H. HUCKABEE NOT SEEING GAINS FROM IOWA WIN ALL EYES ON NEW HAMPSHIRE; TOP CONTENDERSâ?? HOPES PIVOT ON FIRST PRIMARY ELECTION 2008: How the voters upended pollsters Pollsters the most shocked at New Hampshire outcome Read all of the articles, noting when the articles were written, which