Reading and Comprehension Questions for Chapter 6
1. The sample mean is the arithmetic average of al the observation is a sample.
True False
True – see section 6-1.
2. The sample mean is analogous to the center of mass in mechanics.
True False
True – see Section 6-1.
3. The units of the sample standard deviation are the square of the units of measurement
of the original variable.
True False
False - units of the sample variance are the square of the units of measurement of the
original variable.
4. If the sample variance is calculated from a sample of n observations, it has n – 1 degree
of freedom.
True False
True
5. The range of a sample can also be used as a measure of variability.
True False
True – see Equation 6-6.
6. The stem-and-leaf diagram is a visual display of data that preserves each individual
observation in the sample.
True False
True
7. The median of a sample is the most frequently occurring value in the sample.
True False
False – the median of a sample is the value that divides the sample into two equal parts,
with half of the observations on either side of the median. See page
8. Constructing a histogram requires dividing the range of the data into class intervals or
bins, so it does not preserve each individual observation in the sample.
True False
True
9. Histograms can be used with categorical data.
True False
True
10. Histograms provide a reliable visual display of sample data even for small samples.
True False
False – histograms are reliable only for relatively large data sets.
11. Box plots can be used to simultaneously display several feature of a sample, such as
center, spread, departure from symmetry, and identification of outliers.
True False
True
12. Plots of data in time order can reveal features that are not obvious from a histogram
or a stem-and-leaf diagram.
True False
True
13. Probability plots can only be constructed for the normal distribution.
True False
False – probability plots can be constructed for several common distributions.
14. Normal probability plots require some judgment to interpret.
True False
True