chapter 3 Quiz

Which of the following is always​ true?

A. In a symmetric and​ bell-shaped distribution, the​ mean, median, and mode are the same. B. Data skewed to the right have a longer left tail than right tail. C. The mean and median should be used to identify the shape of the distribution. D. For skewed​ data, the mode is farther out in the longer tail than the median. a

Which of the following is NOT a characteristic of the​ mean?

A. The mean is sensitive to outliers. B. The mean is called the average by statisticians. C. The mean takes every data value into account. D. The mean is relatively reliable b

Which of the following is NOT a property of the standard​ deviation?

A. The value of the standard deviation is never negative. B. The units of the standard deviation are the same as the units of the original data. C. When comparing variation in samples with very different​ means, it is good practice to compare the two sample standard deviations. D. The standard deviation is a measure of variation of all data values from the mean. c

A value at the center or middle of a data set is​ a(n) _______.

Measure of center

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

Median Mean Histogram Range range

Which of the following is NOT a measure of​ center?

census

Methods used that summarize or describe characteristics of data are called​ _______ statistics.

descriptive

For data sets having a distribution that is approximately​ bell-shaped, _______ states that about​ 68% of all data values fall within one standard deviation from the mean.

empirical rule

Which of the following is NOT a value in the​ 5-number summary?

mean

The measure of center that is the value that occurs with the greatest frequency is the​ _______.

mode

In modified​ boxplots, a data value is​ a(n) _______ if it is above Q3plus+​(1.5)(IQR) or below Q1minus−​(1.5)(IQR).

outlier

he Range Rule of Thumb roughly estimates the standard deviation of a data set as​ _______.

s=range/4

Whenever a data value is less than the​ mean, _______.

the corresponding z score is negative

A data value is considered​ _______ if its​ z-score is less than minus−2 or greater than 2.

unusual

The square of the standard deviation is called the​ _______.

variance

When a data value is converted to a standardized scale representing the number of standard deviations the data value lies from the​ mean, we call the new value a​ _______.

z score