Share
Explore BrainMass

Confidence Interval

Please see the Attachment for all the 11 Questions.

1) The diameter of Ping- Pong balls manufactured at a large factory is expected to be approximately normally distributed with a mean of 1.30 inches and a standard deviation of 0.40 inch. What is the probability that a randomly selected Ping-Pong ball will have a diameter between 1.31 and 1.33 inches? A) 0.0987 (B) 0.1747 (C) 0.

Critical value, confidence level

Please see the attached file. 1. What is the appropriate critical value for each of the following confidence levels and sample sizes? (Remember that in regard to confidence level this implies two-tails) (a) Critical z-value for an 85% confidence level for sample of size n = 36: (b) Critical t-value for

What is the corresponding confidence interval result of a hypothesis test?

Assume that in a hypothesis test with null hypothesis = 13.0 at 0.05, that a value of 11.0 for the sample mean results in the null hypothesis not being rejected. That corresponds to a confidence interval result of A. The 95% confidence interval for the mean does not contain the value 13.0 B. The 95% confidence interval for

Testing of Hypothesis and Confidence Interval.

Use the traditional method to test the given hypothesis. Assume that the population is normally distributed and that the sample has been randomly selected. 10) In one town, monthly incomes for men with college degrees are found to have a standard deviation of $650. Use a 0.01 significance level to test the claim that for men wi

Use the traditional method to test the given hypothesis.

Use the traditional method to test the given hypothesis. Assume that the samples are independent and that they have been randomly selected 11) In a random sample of 500 people aged 20 24, 22% were smokers. In a random sample of 450 people aged 25 29, 14% were smokers. Test the claim that the proportion of smokers inthe two age

Quantitative methods

The Whistle Stop Cafe in Weems, Georgia, is well known for it's popular homemade icecream. 12. For the demand data in Problem 11, develop a seasonally adjusted forecast for 2006. (Use a linear trend line model to develop a forecast estimate for 2006.) Which forecast model do you perceive to be accurate: the exponential smooth

Confidence Interval

2. We are interested in purchasing a large collection of Palm M515 PDAs but need to have a general idea of how much we must pay for budgetary purposes. Thus, we will construct a confidence interval on the purchase price and in doing so we will assume that selling prices are close to being normally distributed. A sample of selli

Confidence Interval

Assume you need to build a confidence interval for a population mean within some given situation. Naturally, you must determine whether you should use either the t-distribution or the z-distribution or possibly even neither based upon the information known/collected in the situation. Thus, based upon the given information for

Confidence Interval For Effect Of Birth Weight On IQ Score

Please help with the following. Confidence Interval for Effect of Birth Weight on IQ Score: When investigating a relationship between birth weight and IQ, researchers found that 258 subjects with extremely low birth weights (less than 1000 g) had Wechsler IQ scores at age 8 with a mean of 95.5 and a standard deviation of

Probability , hypothesis testing and confidence interval for a set of problems.

I would like help with the following exercises for future reference and a better overall understanding. Thanks! 1. The Los Angeles sheriff classifies crimes by age (in years) of the criminal and whether the crime is violent or nonviolent. As shown below, the sheriff reported a total of 150 crimes last year. Age (in years)

Confidence interval for proportion problem

Please help with the following problems involving confidence intervals. 1. Find the point estimate p-hat and the margin of error for the confidence interval (0.444, 0.484) 2 With destructive testing, sample items are destroyed in the process of testing them. Crash testing of cars is one very expensive example of destruct

Confidence interval for mean

Please see attached. If you can help me with the details of the nine attached questions...with detailed formulas and solutions, I really would appreciate it. 1. Of 139 adults selected randomly from one town, 30 of them smoke. a. Construct a 99% confidence interval for the true percentage of all adults in the town that

Estimation of the Population Proportion or Mean

Please see attached worksheet. If you can give me detailed formulas with answers it would be great. 1. The local Tupperware dealers earned these commissions last month: $4377.47 $3183.76 $1970.16 $2270.88 $3860.06 $2508.55 $1569.64 $4205.30 $1663.68 $3960.71 Assuming the population for the amount of commissions ea

Proportion | Margin of Error

Let's assume that the family size factor for the class was collected from randomly selected students taking Elements of Statistics from FHSU?even though we know the data was not randomly collected from such students. a. First, determine from this sample data the proportion (percentage) of students from families of si

Find the sample size needed for a 95% degree of confidence.

The weekly earnings of middle managers in a large corporation are approximately normally distributed with a standard deviation of 36 dollars. A researcher wishes to estimate the mean weekly earnings. Find the sample size needed if she requires a 95% degree of confidence that the sample mean will not differ from the population by

95% confidence interval & point estimate

I need help solving 95% confidence interval and point estimate problems. A sample of 16 people are used, each one is to keep track of their time with the following result in hours. 1.8, 1.7, 0.9, 1.1, 1.5, 1.5, 1.2, 0.6, 1.4, 0.9, 0.7, 1.8, 1.7, 2.2, 1.5, 1.3 Construct a 95% confidence interval for the amount of time n

You are in charge of selling advertising for radio station KGSM.

Always get overwhelmed by the amount of material when covered at a comprehensive level. Attached is the study material of what to be prepared to cover at the conclusion of this course. I have worked through them but get stumped at several points. Can you provide a systematic approach to these problems and provide a reference to

Confidence interval and t test for mean life time

Always get overwhelmed by the amount of material when covered at a comprehensive level. Attached is the study material of what to be prepared to cover at the conclusion of this course. I have worked through them but get stumped at several points. Can you provide a systematic approach to these problems and provide a reference to