Evidence-Based Practice for Nurses

True/False

1. If the tail of a distribution is skewed to the left, the data are negatively skewed.


2. In a normal distribution, the mean, median, and mode are the same value.


3. If data are highly uniform, a low peak will be observed in a graphic representation
   of the data.

TEST YOUR KNOWLEDGE 13-4

How did you do? 1. T; 2. T; 3. F

13.5 Measures of Variability

At the end of this section, you will be able to:

‹ Describe measures of variability and their use

Measures of variability provide information regarding how different the data

are within a set. These can also be known as measures of dispersion because

they provide information about how data are dispersed around the mean. If

the data are very similar, there is little variability, and the data are considered

to be homogenous. If there is wide variation, the data are considered to be

heterogeneous. Common measures of variation include range, semiquartile

FIGURE 13-5 Example of Kurtosis

High uniformity Moderate uniformity Low uniformity

344 CHAPTER 13 What Do the Quantitative Data Mean?