ECN 221 Quiz Review

The sample statistic, such as the mean or probability that provides the point estimate of the population parameter is known as a

point estimator

A probability distribution of all possible values of a sample statistics is known as

A sampling distribution

Which of the following is NOT a property of a binomial experiment? -Each outcome can be referred to as a success or a failure -The experiment consists of a sequence of n identical trials -The probabilities of the two outcomes can change from one trial to the next -The trials are independent

The probabilities of the two outcomes can change from one trial to the next

For a population with any distribution, the form of the sampling distribution of the sample mean is

always normal for large sample sizes

The center of a normal curve

is the mean of the distribution

For uniform probability density function, the height of the function

is the same for each value of x

For a continuous random variable x, the height of the function at x is

named the probability density function f(x)

A sample of 24 observations is taken from a population that has 150 elements. The sampling distribution of the mean is

normal if the population is normally distributed

A uniform probability distribution is a continuous probability where the probability that the random variable assumes a value in any interval of equal length is

the same for each interval

The random variable x is the number of occurrences of an event over an interval of ten minutes. It can be assumed that the probability of an occurrence is the same in any two time periods of an equal length. It is known that the mean number of occurrences in ten minutes is 5.3. The probability that there are 8 occurrences in ten minutes is

.0771

The random variable x is the number of occurrences of an event over an interval of ten minutes. It can be assumed that the probability of an occurrence is the same in any two times periods of an equal length. It is known the the mean number of occurrences is

.1016

Three percent of the customers of a mortgage company default on their payments. A sample of five customers is selected. What is the probability that exactly two customers in the sample will default on their payments?

0.0082

A simple random sample of 5 observations from a population containing 400 elements were taken, and the following values were obtained. 15, 19, 21, 24, 31 A point estimate of the mean is

22

The random variable x is the number of occurrences of an event over an interval of ten minutes. It can be assumed that the probability of an occurrence is the same in any two time periods of an equal length. It is known that the mean number of occurrences in ten minutes is 5.3. The expected value of the random variable x is

5.3

Twenty percent of the students in a class of 400 are planning to go to graduate school. The standard deviation of this binomial distribution is

8

In the textile industry, a manufacturer is interested in the number of blemishes or flaws occurring in each 100 feet of material. The probability distribution that has the greatest chance of applying to this situation is the _______ distribution.

Poisson