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# Sampling

### Sampling distribution of sample mean....

A. The amount of annual snowfall in a certain mountain range is normally distributed with a mean of 109 inches, and a standard deviation of 10 inches. If 40 snowfall amounts are randomly selected, find &#61549;x-bar for the sampling distribution of sample means with samples of size 40. B. The amount of annual snowfall

### Continuous Probability Distributions and Sampling Distributions

1. Consider a multiple choice examination with 50 questions. Each question has four possible answers. Assume that a student who has done the homework and attended lectures has a 75% probability of answering any question correctly. a) A student must answer 43 or more questions correctly to obtain a grade A. What percentage

### Sampling Error - M&Ms

Total pieces was 57 Color Sample M & M Count Website Count (%) Sampling Error +/- Blue 23.2% 24% .8% Red 10.7% 13% 2.3% Yellow 12.5% 14% 1.5% Orange 17.9% 20% 2.1% Green 17.9% 16%

### Gun Control Legislation and True Proportion

Many people think that a national lobby's successful fight against gun control legislation is reflecting the will of a minority of Americans. A previous random sample of 4000 citizens yielded 2250 who are in favor of gun control legislation. How many citizens would need to be sampled if a 90% confidence intervals was desired to

### How many elephants need to be weighed so find we can be 95% confident to be accurate within 300 pounds? Sample size question.

A study of elephants wishes to determine the average weight of a certain type of elephant. The standard deviation of the population is 500 pounds. How many elephants need to be weighed so find we can be 95% confident to be accurate within 300 pounds?

### Mutual Funds in Random Sample

The Wall Street Journal provides the net asset value, the year-to-date percent return, and the three-year percent return for 555 mutual funds (The Wall Street Journal, April 25, 2003). Assume that a simple random sample of 12 of the 555 mutual funds will be elected for a follow-up study on the size and performance of mutual fu

### Sampling Methods and Statistical Techniques

Compare and contrast three different sampling methods. Please focus on statistical techniques.

### Sample Distribution - New York Stock Exchange

This question has to deal with the sampling distribution of the sample mean. Please see attached file for full problem description. Suppose that the percentage returns for a given year for all stocks listed on the New York Stock Exchange are approximately normally distributed with a mean of 12.4% and a standard deviation of

### Random Sample - An American Society of Investors survey found 30 percent

An American Society of Investors survey found 30 percent of individual investors have used a discount broker. In a random sample of nine individuals, what is the probability. a. Exactly two of the sampled individuals have used a discount broker b. Exactly four of them used a discount broker. c. None of them used a disco

### Secondary Data on Reliable Tests

1) Please share 3 real world examples of problems, which occurred due to the use of secondary data. Be specific about the consequences as well the secondary data used. You may use your own organization or research the net or literature for this one. 2) Can a marketing survey to research consumers' taste be developed for a g

### population and standard deviation

6.16 A population has distribution of unknown shape. The mean of the population is 3,500, and the standard deviation is 600. a. If a sample of 100 values is selected randomly from this population, what is the probability that the sample mean will exceed 3,600? b. If a sample of 200 is selected from the population what is the

### Sampling distribution

Suppose Stat I students ages follow a skewed right distribution with a mean of 24 years old and a standard deviation of 2 years old. If we randomly sampled 150 students, which of the following statements about the sampling distribution of the sample mean age is incorrect? -The mean of the sampling distribution is approximate

### Random Sample - Test Claim

A random sample of 160 car crashes are selected and categorized by age. The are listed below. The age distribution of for the given categories is 18% for under 26, 39% for 26-45, 31% for 46-65, and 12% for over 65. Test the claim that all ages have crash rates proportional to their driving rates (use alpha = .05). Age

### Stats Exercise Questions

11. An example of a measurement made in a nominal scale is: a.the name of the college a student attends. b.a student&#65533;s weight in kilograms. c.a student&#65533;s class rank, such as 25th out of 364. d.a student&#65533;s sex (male or female). e.both (a) and (d). 12. The net asset value of a mutual fund has increased

### US Population Estimation

The President wants an estimate of the proportion of the entire US population who supports his position on gun control (or any policy). The President want the estimate to be within .035(3.5%)of the true proportion. Assume a 95% level of confidence. A. How large a sample is needed? b. Assume a 98% confidence level is want

### Gallup Poll Statistics Question

A news article on a Gallup poll noted that "28 percent of the 1548 adults questioned felt that those who were able to work should be taken off welfare." The article also said, "The margin of error for a sample size of 1548 is plus or minus three percentage points." Explain to someone who knows no statistics what "margin of error

### Double Sampling

A double sampling plan is as follows: (a)Select a random sample of 1 from a lot of 20. If the item inspected is good, accept the lot. If it is defective, take a second sample of one item. (b)If the item in the second sample is good, accept the lot. If it is defective, reject the lot. If a lot 10% defective is submitt

### Sampling for Health Insurance

A health services provider has been reimbursed by a national health insurance organization for a large number of services. It appears that overpayments may have occurred on many of the reimbursements owing to errors made during the billing process or to up-coding (billing for a more complicated service than was actually provided

### Sampling and Sampling Distribution of Employee Absenteeism

Time lost at work from employee absenteeism is an important problem for many companies. The human resources department of Western Electric Corporation has studied the distribution of time lost from absenteeism by individual employees. During a one-year period the department found a mean of 21 days and a standard deviation of 10

### Lower/Upper Bound

An article reports that when each football helmet in a random sample of 44 suspension-type helmets was subjected to a certain impact test, 25 showed damage. Let p denote the proportion of all helmets of this type that would show damage tested in the prescribed manner Give your answers correct to three decimal places Calcul

### Population, sample, parameter, statistic, discrete variable and a continuous variable, independent and dependent variables, scale of measurement

1. A researcher is interested in the effects of humidity on the eating behavior rats. A group of 25 rats is housed in a controlled environment and the researcher measures the amount of food consumed by each rat with humidity set at 20% and again with the humidity set at 80%. a. Identify the population b. Identify the sample

### Sampling Methods

1. In order to assess opinions on healthcare benefits for government employees, a consultant divides the employees into three groups: single, married with no children and married with children. A random sample is then taken within each of these three groups. What kind of sampling method is this? 2. A political pollster tak

### The Answer to Sample Distribution

A population consists of the following 0,0,1,3,6. a. List all samples of 3 and compute the mean of each sample b. Compute the mean of the distribution of sample means and population mean. compare the two values c. Compare the dispersion in the population with that of the sample mean. Also how do you use exel to find the

### How to select a simple random sample in Excel.

In this there is a two-step procedure to select a simple random sample of 30 EAI managers. Use this procedure to select a simple random sample of 50 EAI managers.

### Sampling Distributions

Sampling Distributions. See attached file for full problem description. 11. Appliance magazines provided estimates of the life expectancy of household appliances. A simple random sample of 10 VCRs shows the following useful life in years. 6.5 8.0 6.2 7.4 7.0 8.4 9.5 4.6 5.0 7.4 A. De

### Identify the technique used to produce each sample. (cluster, convenience, random, stratified, systematic)

To determine monthly rental prices of apartment units in San Francisco Bay area, samples were constructed in the following ways. Identify the technique used to produce each sample. (cluster, convenience, random, stratified, systematic): a) Number all the units in the area and use a random number table to select the apartment

### Population Mean

A processor of carrots cuts the green top off each carrot, washes the carrots, and inserts six to a package. Twenty packages are inserted in a box for shipment. To test the weight of the boxes, a few were checked. The mean weight was 20.4 pounds, the standard deviation 0.5 pounds. How many boxes must the processor sample to be 9

### Sampling Methods

Sample Methods Worksheet In each of the following situations determine the type of sampling (simple random sample, cluster sample, stratified sample, convenient sample or systematic sample) that was used. Be able to give an explanation. A hospital is trying to improve its patient services. The hospital administrator rand

### Finding Population with Limited Information

How do I go about finding the population and what the sample is, based on a very limited information? Mass Maritime has a requirement to provide berths on the training ship for all qualified cadets, sounds simple. But like all schools not everyone you accept comes, some leave after orientation, some leave during the fall, so

### Examining Characteristics for Surveys

What is the purpose of a survey? What are three examples of a survey and what potential purpose could each be used for? How can one work to ensure the participants of a survey will have their responses kept private? How can one work to ensure that information gained from a survey is unbiased? Would planning and having