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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 provide

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 1

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

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

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, s

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

99% and 95% Confident Population Estimates

The real estate assessor for a county government wants to study various characteristics of single-family houses in the country. A random sample of 70 houses reveals the following: - Heated area of the house (in square feet): X =1,759, S=380. - 42 houses have central air-conditioning. a. Construct a 99% confidence interv

Means of the Sampling Distributions

1. What symbol is used to represent the mean of the sampling distribution of y-(ybar)? Explain 2. What symbol is used to represent one value from the sampling distribution of y-(ybar)? Explain

Calculating Customers Needed for a Good Sample

What information would you need to know to decide how many customers should be included in the sample? If you wanted to infer the population mean level of satisfaction within plus or minus 0.5 points at a .05 level of significance, how many customers should be included in the sample? Explain how you calculated your answer.

Statistics Study Questions

1) Identify the level of measurement for data that can be classified according to color. a. Ordinal b. Interval c. Nominal d. Ratio 2) Identify the level of measurement for data that are the rankings of a movie ranging from poor to good to excellent. a. Nominal b. Ordinal c. Interval d. Ratio 3) What method of data

The following sample observations were randomly selected

Please help answer the following statistics problems. DQ1: The following sample observations were randomly selected. X: 4, 5, 3, 6, 10 Y: 4, 6, 5, 7, 7 Determine the coefficient of correlation and the coefficient of determination. Interpret. DQ2: The following sample observations were randomly s

Overview of Statistics: Sampling & Job Satisfaction

Provide an overview of the contents of this article and apply the concepts to the Job Satisfaction survey (Job Satisfaction Survey is listed below article). It is important to cover the concept of the techniques used to estimate sample size. Sampling Size: What the Books Don't Tell You Trying to develop the perfect sampling

Sampling distributions and random variables.

It's 10 PM - do you know where your trash can is? In our neighborhood, there have been a varying number of black bear visits each year over the past six years. These visits usually result in a lot of late night noise and mess to clean up in the morning, as the black bears tip over the trash cans and dine on the contents. The

Classification of Data

1 Classify each as nominal-level, ordinal level, interval-level, or ratio-level data. a.time needed for racing cars to make a practice drive _____________________ b. horsepower of automobile engines ___________________________________ c. salaries of cashiers at Acme supermarkets _____________________________ d. r

Change of Variable Technique

Given f(x) = 2x, 0 < x < 1, and a random sample of size two, X1, X2. Show that (see attached) = 7/8 using change of variable techniques. (See attached file for full problem description with proper equations)

Estimate the sample size.

You are studying the effect of two different methods of relaxation therapy. These two have never been compared before. The population mean for method 1 is 100 on a standardized score of relaxation. The population mean for method 2 is 102 on the same standardized test. The population standard deviation for both methods is 5.

Satisfactory sample

A biologist has mixed a spray designed to kill 70 percent of a certain type of insect. If a spraying of 200 such insects killed 130 of them, would you conclude that this mixture was satisfactory?

Employee morale and productivity

Your company has experienced problems with employee morale and productivity. The consultant that was hired submits a report that includes opinions and data collected from 300 secretaries and clerks as well as 75 senior managers. You are in charge of putting the provided recommendations in perspective and comment on the quality o

Population of a Subway Car Statistics Problem

2. The ages of a group of people in a subway car are: 5, 7, 12, 21, 29, 30, 33, 46, 52, and 83. Consider this to be your population. Find µ. Then place each number (age) on a strip of paper, fold them twice, and place them in a hat or bowl. Randomly select 3 separate samples of 5 ages each (be sure to replace the chosen

Sampling Exercises

The commuter train running between Orange County and downtown L.A. has an average speed of 60 mph with a standard deviation of 4.4 mph. As a consultant to the Dept. of Transportation in California, you examined 40 trains and recorded their average speeds. 1) What are the theoretical parameters for the sampling distribution

Test for Single Samples

1. A cognitive psycholgist believes that a particular drug improves short-term memory. The drug is safe, with no side effects. An experiment is conducted in which 8 ramdomly selected subjects are given the drug and then given a short time to memorize a list of ten words. The subjects are then tested for retention 15 minutes

Type of study

In conducting his study of reactions to unemployment, Peter tries to select every 10th unemployed person in his country for a telephone interview. Peter had trouble identifying the entire population (no central lists were kept) and could not contact all the potential participants he could identify, because some of them did not

Sampling method for a telephone survery

I am choosing participants to call for a telephone survery of campus drinking patterns. If I get a list of all the students on campus, and select every 10th student to call have I chosen a. Population b. Simple random sampling c. Systematic random sample d. Representative sample I feel that this is c. Am I in the ball


Edward is conducting a survey of attitudes about the Head Start program. He wants to make sure he has members of all important subgroups of the American population in his sample. What sampling technique should he use? a. Sinple random sampling b. Stratified random sampling c. Quota sampling d. Snowball samplin