Please help with the following problem. Provide step by step calculations in Excel. 17. Consider a 98% confidence interval to estimate a population mean based on a sample of 625 observations with a sample mean of 425 and a sample standard deviation of 150. How many units wide would such a confidence interval be? 18. In a
The material is from 'Confidence Intervals for Difference of Two Means' Please see the attached file for the fully formatted problems.
The material is from 'Confidence Intervals for Difference of Two Means' and 'Confidence intervals for Variances'.
Please see attached
Please see attached
Refer to the accompanying Minitab display of a 95% confidence interval generated using the methods of this section. The sample display results from using a random sample of speeds of drivers ticketed on a section of Interstate 95 in Connecticut. Variable N Mean StDev SE Mean 95% CI Speed
1.) With a margin of error of 0.050; confidence level of 99% ^p and ^q unknown, what is the minimum sample size required to estimate a population proportion or percentage? 2.) Amounts lost by gamblers who took a bus to Atlantic City casino: 99% confidence; n=40, mean of values in sample = $189,standard deviation is known to b
1. A study was conducted to estimate the mean amount spent on birthday gifts for a typical family having two children. A sample of 150 was taken, and the mean amount spent was $225. Assuming a standard deviation equal to $50, find the 95% confidence interval for mu, the mean for all such families. 2. A 95% confidence interv
You are constructing a 95% confidence interval using the information: n = 60, = 65.5, s = 2.5, and E = 0.7. What is the value of the middle of the interval? A. 0.7 B. 2.5 C. 0.95 D. 65.5 What sample size would be needed to estimate the population mean to within one-half standard deviation with 95% confidence?
If 400 households have an annual average income of $50,000 with a standard deviation of $4,000, what is the 90% confidence interval that includes the population household income? Please show all steps of the work, so tht I can understand the formulas/process.
Given the data in problem above, what sample size would you need to have in order to have a 95% confidence interval with an error term of .04?
If 90 out of 120 people asked said they were in favor of cloning, what is the interval that would make you 99% confident that it includes the proportion of people in the entire population that would be in favor of cloning? Given the data in problem above, what sample size would you need to have in order to have a 95% confiden
True or False Questions about Statistics: If in a probability distribution you got the sum of probabilities less than one, it may mean that you skipped some possible outcome/outcomes.
TRUE OR FALSE (With justification)? If in a probability distribution you got the sum of probabilities less than one, it may mean that you skipped some possible outcome/outcomes. Health insurance policies are set up in such a way that a healthy person has a negative expected value, and a sickly person has a positive one.
Please help with the following problem. A stationery store wants to estimate the total retail value of the 300 greeting cards that it has in its inventory. What are the upper and lower limits of the 95% confidence interval estimate of the population total value of all greeting cards that are in inventory if a random sample o
1) The length of time to do a complete full service oil change at Speedy-Lube, is normally distributed with a mean of 15.8 minutes and a standard deviation of 2.2 minutes. Refer to the following table. Table 5A Below normal distribution p(lower) p(upper) z x mean std.dev .0042 .9958 -2.64 10 15.8 2.2 .9719 .0281 1.91 20
The GPA's for 10 randomly selected students are listed below. Construct a 90% confidence interval for the population standard deviation. Assume the data are normally distributed. 2.0 3.2 1.8 2.9 0.9 4.0 3.3 2.9 3.6 .8 a. 1.10, 2.01 b. .32, .85 c. .53, 1.01 d. .81, 1.83
A university dean is interested in determining the proportion of students who receive some sort of financial aid. Rather than examine the records for all students, the dean randomly selects 200 students and finds that 118 of them are receiving financial aid. Use a 99% confidence interval to estimate the true proportion of stud
Assume that the heights of women are normally distributed. A random sample of 20 women have a mean height of 62.5 inches and a standard deviation of 1.3 inches. Construct a 98% confidence interval for the population variance, (lower case sigma)2. a.(0.9,2.1) b.(0.9,4.4) c.(0.7,3.2) d.(0.9,4.2)
Construct a 90% confidence interval for the population mean. Assume the population has a normal distribution. A sample of 15 randomly selected students has a grade point average of 2.86 with a standard deviation of 0.78. a. (2.37, 3.56) b. (2.51, 3.21) c. (2.41, 3.42) d. (2.28, 3.66)
1. Post-It notepads have an unusual adhesive that must be strong enough to stick, but weak enough to not tear the paper when pulled to release. Several batches of adhesives were tested for consistency. Adhesiveness is measured in ounces per square inch (osi). Measurements from six batches of adhesives are given below. Assume the
Among 100 people randomly chosen in a survey, exactly 10 stated that they believed that the elected representatives are honest most of the time.
Among 100 people randomly chosen in a survey, exactly 10 stated that they believed that the elected representatives are honest most of the time. The approximate 99% confidence interval for the percentage of the population who believe that such people are honest most of the time is?
I would like to check my responses to the 3 matching questions for my homework assignment. Bus stats 7 homework 1) The width of a confidence interval will be: Choices: Narrower for 98% confidence than for 90% confidence Wider for a sample size of 64 than for a sample size of 36 Wider for a 99% confidence than for 95%
The average number of miles that 90 truckers drove in a day was 540.0 with a standard deviation of 40 miles. What is the 99% confidence interval of the true mean number of miles driven by all truckers? Enter the response as (beginning of interval, ending of interval) with no spaces between numbers or symbols, EXCEPT after t
Explain the difference between a point estimate and an interval estimate of a parameter? Which is better? Why?
Confidence interval for Data1 & Data2. Using the following data, construct a 95% confidence level interval estimate for the difference between the mean of Data1 and Data2. Data 1 Data 2 n1= 70.0 73 X-bar = 413.5 403.7 s 38.5 30.4
The International Air Transport Association surveys business travelers to develop quality ratings for transatlantic gateway airports.
Please show work. The International Air Transport Association surveys business travelers to develop quality ratings for transatlantic gateway airports. The maximum possible rating is 10. Suppose a simple random sample of 50 business travelers is selected and each traveler is asked to pro-vide a rating for the Miami Internatio
A 95% confidence interval (a t interval) for the lives (in minutes) of Kodak AA batteries is 440 < u < 480. Assume that this result is based on a sample of size 25.
Dear Ota, Provide me the solution with explanation. Thanks 1. A 95% confidence interval (a t interval) for the lives (in minutes) of Kodak AA batteries is 440 < u < 480. Assume that this result is based on a sample of size 25. 1a. What is the value of the sample mean? a. 455 b. 440 c. 445 d. 460 e.
Suppose that the population standard deviation (σ) for a normally distributed standardized test of achievement is known to be 7.20.
I need help with the attached problems. I have the answers and formulas. I just need to show work.
1. At a large publishing company, the mean age of proofreaders is 36.2 years with a standard deviation of 3.7 years. Assuming the age is normally distributed, find the following: a. If a proofreader is selected at random what is probability his/her age will be between 36 and 38 years. b. If a random selected sample 20 proofrea
If a confidence interval for a population mean has length 129.4. Find the margin of error. Please explain how you would find the margin of error in this example.
The Human Relations Department of Electronics, Inc., would like to include a dental plan as part of the benefits package. The question is: How much does a typical employee and his or her family spend per year on dental expenses? A sample of 45 employees reveals the mean amount spent last year was $1,820, with a standard deviatio