SOLUTIONS MAT 167: Statistics Test I - Anthony Tanbakuchi

Solve the problem.
11) If the standard deviation of a set of data is zero, what can you conclude about the set of values?
A) The sum of the values is zero.
B) All values are equal to zero.
C) The sum of the deviations from the mean is zero.
D) All values are identical.
Use the empirical rule to solve the problem.
12) At one college, GPA's are normally distributed with a mean of 2.8 and a standard deviation of
0.6. What percentage of students at the college have a GPA between 2.2 and 3.4?
A) 95.44% B) 99.74% C) 68.26% D) 84.13%
Answer the question, considering an event to be "unusual" if its probability is less than or equal to 0.05.
13) Assume that a study of 300 randomly selected school bus routes showed that 281 arrived on
time. Is it "unusual" for a school bus to arrive late?
A) Yes B) No
Answer the question.
14) Which of the following cannot be a probability?
A) 1
2
B) 3
5
C) 5
3
D) 2
3
Estimate the probability of the event.
15) In a certain class of students, there are 12 boys from Wilmette, 6 girls from Kenilworth, 9 girls
from Wilmette, 7 boys from Glencoe, 5 boys from Kenilworth and 3 girls from Glenoce. If the
teacher calls upon a student to answer a question, what is the probability that the student will be
from Kenilworth?
A) 0.333 B) 0.143 C) 0.262 D) 0.208
Find the indicated probability.
16) A bag contains 4 red marbles, 3 blue marbles, and 5 green marbles. If a marble is randomly
selected from the bag, what is the probability that it is blue?
A) 1
9
B) 1
4
C) 1
5
D) 1
3
17) A sample of 100 wood and 100 graphite tennis rackets are taken from the warehouse. If 14
wood and 13 graphite are defective and one racket is randomly selected from the sample, find
the probability that the racket is wood or defective.
A) 0.565
B) 0.57
C) 0.135
D) There is insufficient information to answer the question.
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