Sampling Distributions
What does the sampling distribution for a sample mean represent?
The distribution of the entire population.
The distribution of possible values for the population mean.
The distribution of individual data points in the sample.
The distribution of possible values for the sample mean if the study were repeated many times.
If a sample of 30 students' test scores has a mean of 78 with a standard deviation of 5, what condition must be considered to use the Central Limit Theorem (CLT) to estimate the sampling distribution of the sample mean?
The population distribution of test scores is uniform.
The scores are independent and identically distributed.
Each student's score must be at least 73 or no more than five points below the mean.
The scores come from a normal distribution with mean 78.
What does an increase in sample size, presuming constant population standard deviation, imply about the precision of the corresponding estimate?
Limited estimates range.
Increased bias.
Improved precision.
Increased randomness.
What is the mean of the sampling distribution of the sample mean equal to?
The population mean ()
The median of the population
The mode of the population
The sample standard deviation ()
What could lead to an overestimate of the population mean income in this study?
Using a small sample size.
Using a large sample size.
Selection bias favoring less financially successful business owners.
Selection bias favoring financially successful business owners.
Which term describes how much a statistic varies in its values when repeatedly computed from different samples?
Sampling variability.
Parameter stability.
Inferential accuracy.
Statistical bias.
Which term refers to the measure of spread in the sampling distribution for the sample mean?
Mean
Range
Sample deviation
Standard error (SE)

How are we doing?
Give us your feedback and let us know how we can improve
If you increase your sample size when creating a sampling distribution of the sample means, what happens to its shape?
It becomes more normal or bell-shaped
It becomes skewed right
Its shape remains unchanged regardless of sample size
It becomes skewed left
What will most likely increase if you decrease your level of confidence when constructing a confidence interval for an unknown population mean?
The sample size required for maintaining the same margin of error
The z* value used in calculating the interval
The width of the confidence interval
The probability that the interval does not contain the true population mean
If a researcher wants to reduce the margin of error in her confidence interval estimation, what action should she take regarding her sample?
Increase the sample size to achieve a lower margin of error because this narrows down the confidence interval.
Collect data from a convenience sampling method, assuming it will be representative enough to decrease margin of error.
Use a stratified random sample instead of a simple random sample to improve precision.
Decrease the sample size to reduce costs, and therefore margin of error by association.