ECON Test 3
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
0.1359
Four hundred registered voters were randomly selected asked whether gun laws should be changed. Three hundred said "yes," and one hundred said "no." Refer to Exhibit 7-2. The point estimate of the proportion in the population who will respond "yes" is
0.75
A population has a mean of 84 and a standard deviation of 12. A sample of 36 observations will be taken. The probability that the sample mean will be between 80.54 and 88.9 is
0.9511
From a population of 500 elements, a sample of 225 elements is selected. It is known that the variance of the population is 900. The standard error of the mean is approximately
1.4847
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
15
The following information was collected from a simple random sample of a population. 16 19 18 17 20 18
18.0
Random samples of size 81 are taken from a process (an infinite population) whose mean and standard deviation are 200 and 18, respectively. The distribution of the population is unknown. The mean and the standard error of the distribution of sample means are
200 and 2
As a general rule, the sampling distribution of the sample proportions can be approximated by a normal probability distribution whenever
Both np ³ 5 and n(1 - p) ³ 5 are true
For a population with an unknown distribution, the form of the sampling distribution of the sample mean is
approximately normal for large sample sizes
A numerical measure from a population, such as a population mean
parameter
The standard deviation of a point estimator is the
standard error
The standard deviation of all possible x-bar values is
standard error of the mean
A numerical measure from a sample, such as a sample mean, is known as
statistic
