15 MCQs in Statistics

1. What is the value of the Pearson coefficient of skewness for a distribution with a mean of 17, median of 12 and standard deviation of 6?
Answer
 

+2.5
 

-2.5
 

+0.83
 

-0.83

 

2. A dot plot and a scatter diagram are different names for the same graph.
Answer 

True
False
 

3The interquartile range is the difference between the values of the first and third quartile, indicating the range of the middle fifty percent of the observations.
Answer
 

True
False
 

4. Quartiles divide a distribution into ten equal parts.
Answer 

True
False
 

5. A dot plot is useful for showing the mode of a distribution.
Answer 

True
False
 

6.A coin is tossed four times. The probability is ¼ or 0.25 that all four tosses will result in a head face up.
Answer 

True
False
 

7. A rug manufacturer has decided to use 7 compatible colors in her rugs. However, in weaving a rug, only 5 spindles can be used. In advertising, the rug manufacturer wants to indicate the number of different color groupings for sale. How many color groupings using the seven colors taken five at a time are there? (This assumes that 5 different colors will go into each rug, i.e., there are no repetitions of color.)
Answer
 

120
 

2,520
 

6,740
 

36
 

8. The joint probability of two independent events, A and B, is computed as: P(A and B) = P(A) P(B).
Answer 

True
False
 

9. The Cunard luxury liner, Queen Elizabeth 2, cannot be docked in Hong Kong and Bangkok at the same time. Events such as these that cannot occur simultaneously are said to be outcomes.
Answer 

True
False
 

10. if two events are mutually exclusive, then P(A or B) = P(A) P(B).
Answer 

True
False
 

11.A group of employees of Unique Services will be surveyed about a new pension plan. In-depth interviews with each employee selected in the sample will be conducted. The employees are classified as follows.
 

Group A 120
Gtoup B 50
Group C 1460
Group D 302
Group E 68
 

What is the probability that the first person selected is either in Group B or Group E ?
Answer
 

0.200
 

0.015
 

0.059
 

0.001
 

12.A student received an "A" on the first test of the semester. The student wants to calculate the probability of scoring an "A" on the second test. Historically, the instructor knows that the joint probability of scoring "A"'s on the first two tests is 0.5. Also, historically, the probability that a student scores an "A" on the second test given that a student scored an "A" on the first test is 0.9. What is the probability that a student will score an "A" on the second test?
Answer
 

0.50
 

0.95
 

0.55
 

0.90
 

13 If an experiment, such as a die-tossing experiment, has a set of events that includes every possible outcome, the set of events is called collectively exhaustive.
Answer 

True
False
 

14. A tire manufacturer advertises, "the median life of our new all-season radial tire is 50,000 miles. An immediate adjustment will be made on any tire that does not last 50,000 miles." You purchased four of these tires. What is the probability that all four tires will wear out before traveling 50,000 miles?
Answer
 

1/10 or 0.10
 

¼ or 0.25
 

1/64 or 0.0156
 

1/16 or 0.0625
 

15.Six basic colors are used in decorating a new condominium. They are applied to a unit in groups of four colors. One unit might have gold as the principal color, blue as a complementary color, red as the accent color and touches of white. Another unit might have blue as the principal color, white as the complimentary color, gold as the accent color and touches of red. If repetitions are permitted, how many different units can be decorated?
Answer
 

7,825
 

25
 

125
 

1,296