Chapter 3 Stats

About​ 95% of all values fall within

2 standard deviations of the mean.

About​ 99.7% of all values fall within

3 standard deviations of the mean.

About​ 68% of all values fall within

1 standard deviation of the mean

If your score on your next statistics test is converted to a z​ score, which of these z scores would you​ prefer:

The z score of 2.00 is most preferable because it is 2.00 standard deviations above the mean and would correspond to the highest of the five different possible test scores.

In modified​ boxplots, a data value is​ a(n) ______ if it is above Q3+​(1.5)(IQR) or below Q1−​(1.5)(IQR).

outlier

Which measure of variation is most sensitive to extreme​ values?

range

Which of the following is always​ true?

In a symmetric and​ bell-shaped distribution, the​ mean, median, and mode are the same.

Suppose that you need to create a list of n values that have a specific known mean. Some of the n values can be freely selected. How many of the n values can be freely assigned before the remaining values are​ determined? (The result is referred to as the number of degrees of​ freedom.)

Of the n​ values, n−1 can be freely selected because the remaining​ value(s) can be expressed in terms of the assigned values and the known mean.

What do these values indicate about a sample mean absolute deviation being used as an estimator of the mean absolute deviation of a​ population?

The sample mean absolute deviation is a biased estimator of the population mean absolute deviation because the sample statistic centers around a different value than the population parameter.

A defunct website listed the​ "average" annual income for Florida as​ $35,031. What is the role of the term average in​ statistics? Should another term be used in place of​ average?

The term average is not used in statistics. The term mean should be used for the result obtained by adding all of the sample values and dividing by the total number of sample values.