Share
Explore BrainMass

Sampling

Random sample of Mean number

A large disaster cleaning company estimates that 30% of the jobs it bids on are finished within the bid time. Looking at a random sample of 8 jobs that is has contracted: Calculate the mean number of jobs completed within the bid time. =

Sampling Distribution of Sample Mean Problems

I need help solving the following problem, please: The fill amount of bottles of a soft drink is normally distributed, with a mean of 2.0 liters and a standard deviation of 0.05 liter. If you select a random sample of 25 bottles, what is the brobability that the sample mean will be a. between 1.99 and 2.0 liters? b. belo

Applied Statistics: Random Sampling

Pulling a name from a hat is one of the techniques of random sampling. However, there are certain pros and cons for this technique? Is this the best technique for random sampling? Please explain and enlighting me.

Mean & S.D. of Sampling Distribution Mean

A population has a mean (Ã?µ) of 615 and a standard deviation (Ã?Æ') of 90. Assume that a sampling distribution of sample means has been Constructed, based on repeated samples of n=400 from this population. a). what would be the value of the mean of the sampling distribution? b. what would be the value of the standard

Sample Size Required - Food Poisoning

Please help with the following problem. Recently, a case of food poisoning was traced to a particular restaurant chain. The source was identified and corrective actions were taken to make sure that the food poisoning would not reoccur. Despite the response from the restaurant chain, many consumers refused to visit the restau

Computing with Sampling Distributions

Recent studies have indicated that the typical New York City teenager spends $500 per year on attending movies. The distribution of amounts spent is normal, with a population standard deviation of $100. We select a random sample of 25 teenagers, and find that the mean amount they spent in the last year was $535. What is the

Sampling Distribution of Sample Mean Probability

1. The Department of Transportation issued a report that said that the average price per gallon of regular unleaded gasoline in the United States is currently $3.85, with a standard deviation of $0.21. A random sample of 49 gasoline stations is taken and their average cost per gallon for regular unleaded gasoline is calculated.

Statistics: Sample of Cannondale bicycle users

A sample of 200 users of Cannondale bicycles was surveyed to ask them then whether they would describe themselves as physically fit, and whether or not they use their bicycles primarily on weekends. The table below contains the result: Uses bicycle primarily on weekends: -Yes -No Physically Fit 20 80 Not Physically Fit 7

Systematic Sampling: Advantages and Disadvantages

Identify a sample design to use for collecting data on rancidity problems with a shipment rice bran. Using nutracea as case study www.nutracea.com. Please include the advantages and disadvantages to systematic sampling. (Ex: http://www.whfoods.com/genpage.php?tname=foodspice&dbid=128).

Samples that are not Normally Distributed

Variables such as height and weight are generally normally distributed (for example, population would take shape of a normal curve). Discuss at least two samples in which you would not expect this to be true. Explain how the shape of the curve would differ from the norm and why it would differ.

Sample for Height, Hourly Wage and Poll

1. People in a large population average 60 inches tall. You will take a random sample and will be given a dollar for each person in your sample who is over 65 inches tall. For example if you sample 100 people and 20 turn out to be over 65 inches tall, you will get $20. Which is better: a sample of size 100 or a sample of siz

Statistics of Doctor Appointment with a New Patient

See attached file for proper formatting. 4. The amount of time a doctor spends in an appointment with a new patient has a mean minutes and standard deviation minutes. The distribution of times is not normal. (a) Suppose a sample of 5 new patient appointments is selected. What can you say about the sampling dis

Derive Inverse Transformation

Can you please help me derive the inverse transformation algorithm for generating a random variate? Derive the inverse transformation algorithm for a generating a random variate from the following distribution (assume a<b). 1/ (b-a) if a<=x<=b f(x) = 0 otherwise

Three Worked Through Solutions for Statistics Problems

Please see attached file. Suppose you have drawn a sample of size 200 from a college and, for each student, recorded the gender of the student, and how interested the student was in watching sports on television on a 1-7 scale (1: not interested at all, 7: very interested). The results are summarized as the following cross-ta

Statistics Probability for Sample Means

1. Suppose you have drawn a simple random sample of 10 students from a college campus and recorded how many hours each student surfed the internet during the first week of February, 2010. Results: Student: 1 2 3 4 5 6 7 8 9 10 Hours of Internet Surfing: 9 12 4 10 5 18 8 12 6 6 For this sample, c

Mean fat content for a sample of farm-raised trout

Seventy million pounds of trout are grown in the U.S. every year. Farm-raised trout contain an average of 32 grams of fat per pound, with a standard deviation of 7 grams of fat per pound. A random sample of farm-raised trout is selected. The mean fat content for the sample is 29.7 grams per pound. Find the probability of observ

Time measurements for sample size for a maximum error of estimation

By measuring the amount of time it takes a component of a product to move from one workstation to the next, an engineer has estimated that the standard deviation is 3.92 seconds. Answer each of the following (show all work): (A) How many measurements should be made in order to be 90% certain that the maximum error of esti

Survey Sampling for hours spent exercising daily in a certain community

Suppose that a survey is being planned for purposes of estimating the average number of hours spent exercising daily by adults (18 years of age or older) living in a certain community. A list of all individuals living in the town is not available; however, a list of all households is available at the office of the town clerk. Fo

Ethics of Sales People

ETHICS OF SALESPEOPLE Within marketing, the area of personal sales has long suffered from a poor ethical image, particularly in the eyes of college students. An article investigated whether such options by college students are a function of the tupe of sales job (high tech versus low tech) and/or the sales task (new account

Longmont Computer Leasing Company: Mean number of pages printed in a month

The Longmont Computer Leasing Company leases computers and peripherals like laser printers. The printers have a counter that keeps track of the number of pages printed. The company wishes to estimate the mean number of pages that will be printed in a month on its leased printers. The plan is to select a random sample of printers

Statistics: Ad for Moisturizing Lotion; Adult Use of Sunscreen

Can you assist me, in your own words, in setting up a full statistical and word explanation for the following: a. In an ad for moisturizing lotion, the following claim is made: '..it's the #1 dermatologist recommended brand.' What is misleading about the claim? b. In a recent article, the author states that 71% of adults d

Statistics

Please show all of the steps and processes used to solve each problem. 1. Suppose we are researching the attitudes of first year medical students at a local University. Using this example, describe in your own words how you would go about determining this through: a. Drawing a random sample b. Drawing a systematic sample

Find sample variances and compute pooled variances

One sample has SS = 48 and a second sample has SS = 32. When both samples have n =5, what is each sample variance and computed pooled variance? Then, if the first sample is n = 5 and the second is n = 9, what are the sample variances and the pooled variances?

Research, Sampling, Hypothesis Testing and Proportions

1. What does it mean to replicate research, and how does this impact our confidence? 2. What is the risk associated with volunteer samples? 3. What is the difference between null hypothesis and a research hypothesis? 4. Convert the following percentages to proportions: 62.7%; 0.3%; 4.2%.

Selections and Evaluation: Statistics Problem

1-Jan 2-Jan 3-Jan 4-Jan 5-Jan 6-Jan 7-Jan 8-Jan 9-Jan 10-Jan 15 3 3 4 1 6 0 6 1 4 The next 5 days of phone calls received were as follows: 11 Jan (5) 12 Jan(6) 13 Jan (4) 14 Jan (3) 15 Jan (5) Welcome to module four's SLP. For this module, continue to collect data for five days. Is the larger sample