Statistics problems (26)
Use the following data for questions 1 through 4: 5,12,6,8,5,6,7,5,12,4.
• The median is
• 5
• 6
• 7
• 8
• None of the above
• The mode is
• 5
• 6
• 7
• 8
• None of the above
• The mean is
• 5
• 6
• 7
• 8
• None of the above
• The 75th percentile is
• 5
• 6
• 7
• 8
• None of the above
Use the following data for questions 5 through 9: 3,5,12,3,2.
• The variance is
• 80
• 4.062
• 13.2
• 16.5
• None of the above
• The standard deviation is
• 8.994
• 4.062
• 13.2
• 16.5
• None of the above
• The coefficient of variation is
• 72.66%
• 81.24%
• 264%
• 330%
• None of the above
• The range is
• 1
• 2
• 10
• 12
• None of the above
• The interquartile range is
• 1
• 2
• 10
• 12
• None of the above
10. In a post office, the mail boxes are numbered from 100 to 2300. these numbers
represent
a. qualitative data
b. quantitative data
c. either quantitative or qualitative data
d. since the numbers are sequential, the data is quantitative
e. None of the above answers is correct
11. The process of analyzing sample data in order to draw conclusions about characteristics of a population is called
a. descriptive statistics
b. statistical inference
c. data analysis
d. data summarization
e. None of the above answers is correct
12. In a sample of 1600 registered voters, 912 voters or 57%, approve of the way the President is doing his job.
The 57% approval is an example of
a. a sample
b. descriptive statistics
c. statistical inference
d. a population
e. None of the above answers is correct
13. The sum of the relative frequencies of all classes will always equal
a. the sample size
b. the number of classes
c. one
d. any value larger than one
e. None of the above answers is correct
14. Of five letters (A,B,C,D, and E), two letters are to be selected at random. How many possible selections are there?
a. 20
b. 7
c. 5!
d. 10
e. 22
15. Given that event E has a probability of 0.25, the probability of the complement of event E(E’)
a. cannot be determined with the above information
b. can have any value between zero and one
c. must be 0.75
d. is 0.25
e. None of the above
16. Assume your favorite team has 2 games left to finish the season. The outcome of each game can be win, lose or tie. the number of possible outcomes is
a. 2
b. 4
c. 6
d. 8
e. None of the above
17. An experiment consists of tossing 4 coins successively. The number of sample points in this experiment is
a. 16
b. 8
c. 4
d. 2
e. None of the above
18. 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. both a and c are correct
e. None of the above
19. The addition law is potentially helpful when we are interested in computing the probability of
a. independent events
b. intersection of two events
c. union of two events
d. conditional events
e. None of the above
20. If a penny is tossed four times and comes up heads all four times, the probability of heads on the fifth trial is
a. 0
b. 1/32
c. 0.5
d. larger than the probability of tails
e. None of the above
21.If P(A) = 0.68, P(B) = 0.97 and P(AUB) =0.71; then P(A intersect B) =
a. 0.6597
b.1.6500
c. 0.6500
d. 0.94
e. None of the above
22. If P(A) = 0.85, P(A intersect B) = 0.72, P(AUB) = 0.66, then P(B) =
a. 0.15
b. 0.53
c. 0.28
d. 0.15
e. None of the above
23. Assume n objects are to be selected from a set of N objects. If the order of selection is important, the counting rule for the number of possibilities is
a. permutation
b. combination
c. either combination or permutation depending on the value of N
d. either combination or permutation depending on the value of n
e. None of the above
24. AMR is a computer consulting firm. The number of new clients they have obtained each month has ranged from 0 to 6. The number of new clients has the probability which is shown below:
Number of New Clients Probability
0 0.05
1 0.10
2 0.15
3 0.35
4. 0.20
5. 0.10
6 0.05
The expected number of new clients per month is
a. 6
b. 0
c. 3.05
d. 21
e. more than 6
25. Z is a standard normal random variable. The P(1.20<=Z<=1.85) equals
a. 0.4678
b. 0.3849
c. 0.8527
d. 0.0829
e. None of the above
26. Z is a standard normal random variable. The P(1.41 < Z < 2.85) equals
a. 0.4772
b. 0.3413
c. 0.8285
d. 0.1359
e. None of the above
27. X is a normally distributed random variable with a mean of 8 and a standard deviation of 4. The probability that x is between 1.48 and 15.56 is
a. 0.0222
b. 0.4190
c. 0.5222
d. 0.9190
e. None of the above
