STATS FINAL
The statement is true.
A data set can have the same mean, median, and mode.
The range is found by subtracting the minimum data entry from the maximum data entry.
Explain how to find the range of a data set.
The standard deviation is the positive square root of the variance. The standard deviation and variance can never be negative. Squared deviations can never be negative.
Explain the relationship between variance and standard deviation. Can either of these measures be negative? Explain.
When given a data set, one would have to determine if it represented the population or if it was a sample taken from the population. If the data are a population, then sigma is calculated. If the data are a sample, then s is calculated.
Given a data set, how do you know whether to calculate stand deviation or s?
The sum of the data entries divided by the number of entries.
How do you find the population mean?
nominal
If the data set isn't skewed what it is?
The mode is the data entry that has the highest frequency.
In this distribution, how is the mode determined?
When calculating the population standard deviation, the sum of the squared deviation is divided by N, then the square root of the result is taken. When calculating the sample standard deviation, the sum of the squared deviations is divided by -1, then the square root of the result is taken.
Let N be the number of data entries in a population and n be the number of data entries in a sample data set. Choose the correct answer below.
The statement is false. All quantitative data set have medians.
Some quantitative data sets do not have medians.
Mode
The _____ best describes a nominal data set.
True.
The mean is the measure of central tendency most likely to be affected by an extreme value (outlier).
The Empirical Rule assumes the distribution is aproximately symmetric and bell-shaped and Chebychev's Theorem makes no assumptions.
What is a difference between the Empirical Rule and Chebychev's Theorem?
It uses only two entries from the data set.
What is a disadvantage of using the range as a measure of variation?
Both estimate proportions of the data contained within k standard deviations of the mean.
What is a similarity between the Empirical Rule and Chebychev's Theorem?
It is easy to compute.
What is an advantage of using the range as a measure of variation?
The sum of the data entries divided by the number of entries.
What is the definition of mean?
The value that lies in the middle of the data when the data set is ordered.
What is the definition of median?
The data entry that occurs with the greatest frequency.
What is the definition of mode?
Median
When the data set is skewed, the _______is the preferred measure of central tendency.
The units of variance are squared. Its units are meaningless.
Why is the standard deviation used more frequently than the variance?
