Exam 9: Sampling Distributions

A CPA knows from past history that the average accounts receivable for a company is $521.72 with a standard deviation of $584.64.If the auditor takes a simple random sample of 100 accounts, what is the probability that the mean of the sample is within $120 of the population mean?

Consider an infinite population with a mean of 100 and a standard deviation of 20.A random sample of size 64 is taken from this population.The standard deviation of the sample mean equals 2.50.

Suppose the ages of students in your program follow a positively skewed distribution with mean of 24 years and a standard deviation of 4 years.If we randomly sampled 100 students, which of the following statements about the sampling distribution of the sample mean age is NOT true?

Magazines A local magazine store sells an average of 2,100 magazines per day, with a standard deviation of 500 magazines.Consider a sample of 60 days of operation. -{Magazines Narrative} Find the expected value and the standard error of the sample mean.

As the number of throws of a fair die increases, the probability that the sample mean is close to (the number) ____________________ increases.

Random samples of size 81 are taken from an infinite population whose mean and standard deviation are 45 and 9, respectively.The mean and standard error of the sampling distribution of the sample mean are:

Heights of Men The heights of men in the USA are normally distributed with a mean of 68 inches and a standard deviation of 4 inches. -{Heights of Men Narrative} What is the probability that the mean height of a random sample of 36 men is greater than 70 inches?

A sampling distribution is a probability distribution for a statistic, not a parameter.

A sample of size 200 is taken at random from an infinite population.Given that the population proportion is 0.60, the probability that the sample proportion is greater than 0.58 is:

To find the binomial probability P(X $\le$ 4) we calculate the area under the normal curve to the ____________________ (left/right) of the number ____________________.

Retirees A sample of 50 retirees is drawn at random from a normal population whose mean age and standard deviation are 75 and 6 years, respectively. -{Retirees Narrative} What is the probability that two randomly selected retirees are over 73 years of age?

The finite population correction factor should be used:

For a sample size of 1, the sampling distribution of the mean is normally distributed:

The Central Limit Theorem permits us to draw conclusions about a population based on a sample alone, without having any knowledge about the distribution of that population.And this works no matter what the sample size is.

The standard error of the sample proportion gets larger as:

Temporary Worker Productivity A temporary worker productivity is normally distributed.One worker produces an average of 84 units per day with a standard deviation of 24.Another worker produces at an average rate of 74 per day with a standard deviation of 25. -{Temporary Worker Productivity Narrative} What is the probability that during one week (5 working days), worker 1 will outproduce worker 2 on average?

As n gets ____________________, the shape of the sampling distribution of becomes increasingly bell shaped.

Given a binomial distribution with n trials and probability p of a success on any trial, a conventional rule of thumb is that the normal distribution will provide an adequate approximation of the binomial distribution if

The standard error of the sampling distribution of the sample proportion , when the sample size n = 100 and the population proportion p = 0.30, is 0.0021.

If two random samples of size 36 each are selected independently from two populations with variances 25 and 16, then the standard error of the sampling distribution of the sample mean difference, , is 5-4 = 1.