DESCRIPTIVE STATISTICS: NUMERICAL MEASURES

MULTIPLE CHOICE QUESTIONS

In the following multiple choice questions, circle the correct answer.

1.Which of the following provides a measure of central location for the data? a.standard deviation

b.mean

c.variance

d.range

Answer: b

2.A numerical value used as a summary measure for a sample, such as sample mean, is known as a

a.population parameter

b.sample parameter

c.sample statistic

d.population mean

Answer: c

3.Since the population size is always larger than the sample size, then the sample statistic

a.can never be larger than the population parameter

b.can never be equal to the population parameter

c.can be smaller, larger, or equal to the population parameter

d.can never be smaller than the population parameter

Answer: c

4.( is an example of a

a.population parameter

b.sample statistic

c.population variance

d.mode

Answer: a

5.The hourly wages of a sample of 130 system analysts are given below.

mean = 60range = 20

mode = 73variance = 324

median = 74

The coefficient of variation equals

a.0.30%

b.30%

c.5.4%

d.54%

Answer: b

6.The variance of a sample of 169 observations equals 576. The standard deviation of the sample equals

a.13

b.24

c.576

d.28,461

Answer: b

7.The median of a sample will always equal the

a.mode

b.mean

c.50th percentile

d.all of the above answers are correct

Answer: c

8.The median is a measure of

a.relative dispersion

b.absolute dispersion

c.central location

d.relative location

Answer: c

9.The 75th percentile is referred to as the

a.first quartile

b.second quartile

c.third quartile

d.fourth quartile

Answer: c

10.The pth percentile is a value such that at least p percent of the observations are

a.less than or equal to this value

b.less than this value

c.more than or equal to this value

d.more than this value

Answer: a

11.The difference between the largest and the smallest data values is the

a.variance

b.interquartile range

c.range

d.coefficient of variation

Answer: c

12.The first quartile

a.contains at least one third of the data elements

b.is the same as the 25th percentile

c.is the same as the 50th percentile

d.is the same as the 75th percentile

Answer: b

13.Which of the following is not a measure of central location?

a.mean

b.median

c.variance

d.mode

Answer: c

14.If a data set has an even number of observations, the median

a.cannot be determined

b.is the average value of the two middle items

c.must be equal to the mean

d.is the average value of the two middle items when all items are arranged in ascending order

Answer: d

15.Which of the following is a measure of dispersion?

a.percentiles

b.quartiles

c.interquartile range

d.all of the above are measures of dispersion

Answer: c

16.The most frequently occurring value of a data set is called the

a.range

b.mode

c.mean

d.median

Answer: b

17.The interquartile range is

a.the 50th percentile

b.another name for the variance

c.the difference between the largest and smallest values

d.the difference between the third quartile and the first quartile

Answer: d

18.If index i (which is used to determine the location of the pth percentile) is not an integer, its value should be a.squared

b.divided by (n – 1)

c.rounded down

d.rounded up

Answer: d

19.When the data are skewed to the right, the measure of Skewness will be a.negative

b.zero

c.positive

d.one

Answer: c

20.When data are positively skewed, the mean will usually be a.greater than the median

b.smaller than the median

c.equal to the median

d....