1. 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
2. The 50th percentile is the
a. mode
b. median
c. mean
d. third quartile
3. The difference between the largest and the smallest data values is the
a. variance
b. interquartile range
c. range
d. coefficient of variation
4. 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. positive
5. The numerical value of the standard deviation can never be
a. larger than the variance
b. zero
c. negative
d. smaller than the variance
6. Which of the following symbols represents the standard deviation of the population
a. σ2
b. σ
c. μ
d. x ¯
7. Which of the following symbols represents the mean of the population
a. σ2
b. σ
c. μ
d. x ¯
8. Which of the following symbols represents the mean of the sample
a. σ2
b. σ
c. μ
d. x ¯
9. Two events are mutually exclusive
a. if their intersection is 1
b. if they have no sample points in common
c. if their intersection is 0.5
d. None of these alternatives is correct
10. The range of probability is
a. any value larger than zero
b. any value between minus infinity to plus infinity
c. zero to one
d. any value between -1 to 1
11. The sum of the probabilities of two complementary events is
a. 0
b. 0.5
c. 0.75
d. 1
12. The union of events A and B is the event containing
a. all the sample points belonging to B or A
b. all the sample points belonging to A or B
c. all the sample points belonging to A or B or both
d. all the sample points belonging to A or B, but not both
13. Events A and B are mutually exclusive. Which of the following statements is also true?
a. A and B are also independent
b. P(A ∪ B) = P(A)P(B)
c. P(A ∪ B) = P(A) + P(B)
d. P(A ∩ B) = P(A) + P(B)
14. The set of all possible sample points (experimental outcomes) is called
a. a sample
b. an event
c. the sample space
d. a population
15. If A and B are independent events, then
a. P(A) must be equal to P(B)
b. P(A) must be greater than P(B)
c. P(A) must be less than P(B)
d. P(A) must be equal to P(A¦B)