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Sampling Distribution

Sampling distribution of proportion

A simple random sample of size 100 is selected from a population with p=.40. a. What is the expected value of p? b. What is the standard error of p? c. Show the sampling distribution of p. d. What does the sampling distribution of p show?

Sampling distribution of a sample mean

CRA CDs Inc. wants the mean lengths of the "cuts" on a CD to be 145 seconds (2 minutes and 25 seconds). This will allow the disk jockeys to have plenty of time for commercials within each 10-minute segment. Assume the distribution of the length of the cuts follows the normal distribution with a population standard deviation of 1

Sampling Distribution of Sample Mean Random Sizes

A large number of simple random samples of size n = 85 are obtained from a large population of birth weights having a mean of 3420 g and a standard deviation of 495 g. The sample mean is calculated for each sample. A) What is the approximate shape of the distribution of the sample means? B) Determine the expected mean and the

Mean of Sampling Distribution

A population has a mean (µ) of 24.12 and a standard deviation (Æ') of 4. Assume that a sampling distribution of sample means has been constructed. Based on repeated samples of n=100 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 er

Sampling Distributions for level of nitrogen oxides in the exhaust of cars

The level of nitrogen oxides (NOX) in the exhaust of cars of a particular model varies Normally with mean 0.2g/mi and standard deviation 0.05g/mi. A company has 25 cars of this model in its fleet. What is the level L such that the probability that the average NOX level mean for the fleet is greater than L is only 0.01?

Solid missile fuel and particle size distribution

An important factor in solid missile fuel is the particle size distribution. Significant problems occur if the particle sizes are too large. From production done in the past, it has been determined that the particle size in microns distribution is characterized by: f(x) = 3x^-4 x>1 0 elsewhere

Sampling Distributions of happy customers of Countybank

Historically, the percentage of Countybank customers who are happy with customer service has been 63%. Suppose we wish to use the results of a survey of 500 Countybank customers to justify the claim that more than 63% of all current customers are happy with customer service. The survey finds that 330 of 500 randomly selected C

Sampling distribution: Sample Means; Bike shop mean repair cost exceeding $16

1. All possible sample of size of 150 was collected from a population and listed the sample means for each of these samples. (a) If the average of the sample means is 450.55 what would be the numerical value of the true population mean. Discuss (b) If the standard deviation of the sample means is 12.25 determine the stan

Sample statistics and sampling distribution

9 A computer simulation can itself be regarded as a sampling process. Suppose that a simulation study is done concerning the time required to complete a research and development project. There is considerable uncertainty in the times required to complete the various pieces of the project, so the overall completion time has co

Shape of the distribution of the Sample Mean

CRA CDs, Inc. wants the mean lengths of the "cuts" on a CD to be 135 seconds (2 minutes and 15 seconds). This will allow the disk jockeys to have plenty of time for commercials within each 10-minute segment. Assume the distribution of the length of the cuts follows the normal distribution with a standard deviation of 8 seconds.

Sample Size: T-Distribution

As a sample size approaches infinity, how does the t-distribution compare to the normal z distribution? When you draw a sample from a normal distribution, what can you conclude about the sample distribution? Explain.

Statistics - One-tail , Two-tail , and Sampling Distribution

A can of peeled tomatoes is supposed to contain an average of 19 ounces of tomatoes (excluding the juice). The actual weight is a normally distributed random variable whose standard deviation is known to be 0.25 ounces. (a) In quality control, would a one-tail or two-tailed test be used? Why? (b) Explain the consequences of depa

Sampling and Sampling Distribution

1. A new kind of alkaline is believed to last an average of 25 hours of continuous use (in a given kind of flashlight). Assume that the population standard deviation is 2 hours. Of a random sample of 100 batteries is selected and tested, is it likely that the average battery in the sample will last less than 24 hours of contin

sampling distribution of mean .

A person asks, "what do you think is the ideal number of children for a family to have?" The 497 females who responded had a median of 2, mean of 3.02, and a standard deviation of 1.81. How do I find the point estimate of the mean and the standard error of the sample mean?

Transformation of Functions

You have been given the sample {0.28, 0.09, 0.22, 0.29, 0.25, 0.68, 0.11, 0.07, 0.02, 0.54} drawn from a population distributed according to ..... (a) Suppose that, for the sample provided, the sample mean is less than the population mean. What does this imply about θ? (b) Suppose that you are further told that, for t

Sampling distribution of sample mean

1. Americans have become increasingly concerned about the rising cost of Medicare. In 1990, the average annual Medicare spending per enrollee was $3267; in 2003, the average annual Medicare spending per enrollee was $6883 (Money, Fall 2003). Suppose you hired a consulting firm to take a sample of fifty 2003 Medicare enrollees

Sampling distribution of mean

A sample of size n is selected at random from an infinite population. As n increases, which of the following statements are true? A) The population standard deviation decreases B) The standard error of the sample mean decreases C) The population standard deviation increases D) The standard

Sampling distribution of sample mean

Suppose the annual consumption of chicken mean is 20.84 pounds per person and that the standard deviation for the consumption of chicken per person is 9.193 pounds. The mean weight of chicken consumed for a sample of 200 randomly selected people is one value of many that form the sampling distribution of sample means. Descri

Properties of distributions.

In these problems, the word average refers to the arithmetic mean x̄ or µ, properties 4. General suppose that x has a distribution with µ = 72 and σ= 8. A). If random samples of size n = 16 are selected, can we say anything about the x̄ distribution of sample means? B). If the original x distribution is

Sampling Distributions on Consumer Buying Decisions

A survey of 2,645 consumers by DDB Stern Worldwide of Chicago for public relations agency Merc Brothers showed that how a company handles a crisis when at fault is one of the top influences in consumer buying decisions, with 73% claiming it is an influence. Quality of product was the number one influence, with 96% of consumers

Sampling distribution of sample mean...

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spend studying per week. Based on a simple random sample, they surveyed 144 students. The statistics showed that students studied an average of 20 hours per week with a standard deviation of 10 hours

Probability Distributions.

Please help me with this statics problem. The probability distribution shown here describes a population of measurements that can assume values of 0, 2, 4, and 6, each of which occurs with the same relative frequency: x 0 2 4 6 p(x) 1/4 1/4 1/4 1/4 a. List all the different samples of n = 2 measurements that can be s

Sampling Distribution of Sample Mean: Body Repair on Automobile

The average estimate for the body repair on an automobile is $1540. From insurance records it has been determined that the population standard deviation is $640. A. What is the probability of selecting a sample of 49 and the sample mean being above $1600?

Sampling Distributions

35. The Democrat and Chronicle reported that 25% of the flights arriving at the San Diego airport during the first five months of 2001 were late (Democrat and Chronicle), July 23, 2001). Assume the population proportion is p = .25 A. Show the sampling distribution of _ , the proportion of late flights in a sample of10

Quantitative Analysis - diameter of Ping-Pong balls

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 0.04 inch. What is the probability that a randomly selected Ping-Pong ball will have a diameter... a. less than 1.28 inches? b. Between 1.31 and

Sampling Distribution of the Sample Mean - Normal Distribution

State whether the sampling distribution of the sample mean is normally distributed, or approximately normally distributed, or not normally distributed when computed from: a)A sample of 10 metabolic rations, where the population is normally distributed b)A Sample of 100 resting vagal tone in healthy adults, where the populati

Valid probability distribution

A) Which of the following is a valid probability assignment for an event whose sample space is {A, B, C, D, F}? b) Explain the reason why each of the other two is not a valid probability assignment. Outcome Probability A 0.15 0.25 0.25 B 0.6 0.5 0.6 C 0.2 0.21 0.2 D 0.05

Probability of the Sample Mean of Plumbers in a City

The average weekly earnings of the plumbers in a city is {$750} with a standard deviation of {$40}. Assume that we select a random sample of {n=64 plumbers} what is the probability that the sample mean will be greater than $740?