1.Statistical inferencea. refers to the process of drawing inferences about the sample based on the characteristics of

the populationb. is the same as descriptive statisticsc. is the process of drawing inferences about the population based on the information taken

from the sampled. is the same as a census

ANS: C2.The collection of all elements of interest in a particular study is

a. the populationb. the samplingc. statistical inferenced. descriptive statistics

ANS: A3.The height of a building, measured in feet, is an example of

a. qualitative datab. either qualitative or quantitative datac. feet datad. quantitative data

ANS: D4.An interviewer has made an error in recording the data. This type of error is known as

a. an experimental errorb. a data acquisition errorc. a non-experimental errord. a conglomerate error

ANS: B

4. Qualitative data can be graphically represented by using a(n)a. histogramb. frequency polygonc. ogived. bar graph

ANS: D5. The relative frequency of a class is computed by

a. dividing the midpoint of the class by the sample sizeb. dividing the frequency of the class by the midpointc. dividing the sample size by the frequency of the classd. dividing the frequency of the class by the sample size

ANS: D

5. A graphical presentation of the relationship between two variables isa. an ogiveb. a histogramc. either an ogive or a histogram, depending on the type of data

d. a scatter diagram

ANS: D6. A histogram is said to be skewed to the left if it has a

a. longer tail to the rightb. shorter tail to the rightc. shorter tail to the leftd. longer tail to the left

ANS: D

7. In a scatter diagram, a line that provides an approximation of the relationship between the variables is known asa. approximation lineb. trend linec. line of zero interceptd. line of zero slope

ANS: B

8.When computing the mean of a set of values xi, the value of xia. can never be zerob. can never be negativec. must always be positived. can be any value

ANS: D9. In computing the mean of a sample, the value of xi is divided by

a. nb. n - 1c. n + 1d. n - 2

ANS: A

10. If the variance of a data set is correctly computed with the formula using n - 1 in the denominator, which of the following is true?a. the data set is a sampleb. the data set is a populationc. the data set could be either a sample or a populationd. the data set is from a census

ANS: A11. In computing descriptive statistics from grouped data,

a. data values are treated as if they occur at the midpoint of a classb. the grouped data result is more accurate than the ungrouped resultc. the grouped data computations are used only when a population is being analyzedd. None of these alternatives is correct.

ANS: A

12. The mean of the samplea. is always smaller than the mean of the population from which the sample was takenb. can never be zeroc. can never be negatived. None of these alternatives is correct.

ANS: D13. The variance of the sample

a. can never be negativeb. can be negativec. cannot be zerod. cannot be less than one

ANS: A

14. If A and B are independent events with P(A) = 0.65 and P(A B) = 0.26, then, P(B) =a. 0.400b. 0.169c. 0.390d. 0.650

ANS: A15. If P(A) = 0.4, P(B | A) = 0.35, P(A B) = 0.69, then P(B) =

a. 0.14b. 0.43c. 0.75d. 0.59

16. A graphical device used for enumerating sample points in a multiple-step experiment is aa. bar chartb. pie chartc. histogramd. None of these alternatives is correct.