Exam 7: Sampling and Sampling Distributions

Exhibit 7-5 Random samples of size 17 are taken from a population that has 200 elements, a mean of 36, and a standard deviation of 8. -An automotive repair shop has determined that the average service time on an automobile is 2 hours with a standard deviation of 32 minutes. A random sample of 64 services is selected. a.What is the probability that the sample of 64 will have a mean service time greater than 114 minutes? b.Assume the population consists of 400 services. Determine the standard error of the mean.

In a local university, 10% of the students live in the dormitories. A random sample of 100 students is selected for a particular study. a.What is the probability that the sample proportion of students living in the dormitories is between 0.172 and 0.178? b.What is the probability that the sample proportion of students living in the dormitories is greater than 0.025?

Exhibit 7-4 A random sample of 121 bottles of cologne showed an average content of 4 ounces. It is known that the standard deviation of the contents (i.e., of the population) is 0.22 ounces. -Refer to Exhibit 7-4. The standard error of the mean equals

The set of all elements of interest in a study is

A population has a mean of 80 and a standard deviation of 7. A sample of 49 observations will be taken. The probability that the mean from that sample will be larger than 82 is

A department store has determined that 25% of all their sales are credit sales. A random sample of 75 sales is selected.a What is the probability that the sample proportion will be greater than 0.34? b.What is the probability that the sample proportion will be between 0.196 and 0.354? c.What is the probability that the sample proportion will be less than 0.25? d.What is the probability that the sample proportion will be less than 0.10?

A population has a mean of 180 and a standard deviation of 24. A sample of 64 observations will be taken. The probability that the mean from that sample will be between 183 and 186 is

A single numerical value used as an estimate of a population parameter is known as

In computing the standard error of the mean, the finite population correction factor is not used when

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

A sample of 400 observations will be taken from a process (an infinite population). The population proportion equals 0.8. The probability that the sample proportion will be greater than 0.83 is

A numerical measure from a population, such as a population mean, is called

A simple random sample of 64 observations was taken from a large population. The population standard deviation is 120. The sample mean was determined to be 320. The standard error of the mean is

The population being studied is usually considered ______ if it involves an ongoing process that makes listing or counting every element in the population impossible.

The life expectancy in the United States is 75 with a standard deviation of 7 years. A random sample of 49 individuals is selected. a.What is the probability that the sample mean will be larger than 77 years? b.What is the probability that the sample mean will be less than 72.7 years? c.What is the probability that the sample mean will be between 73.5 and 76 years? d.What is the probability that the sample mean will be between 72 and 74 years? e.What is the probability that the sample mean will be larger than 73.46 years?

When the population has a normal distribution, the sampling distribution of is normally distributed

As the sample size increases, the

The sample mean is the point estimator of

The number of random samples (without replacement) of size 3 that can be drawn from a population of size 5 is