Test 2B
MATH 1107
DeMaio
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the
question.
Solve the problem.
1) A consumer organization estimates that 30% of the households in a particular community have
one television set, 38% have two sets, and 20% have three or more sets. What is the probability
that a household chosen at random has no television sets?
A) 0.88
B) 0.18
C) 0.16
D) 0.12
E) 0
2) A survey revealed that 31% of people are entertained by reading books, 39% are entertained by
1)
2)
watching TV, and 30% are entertained by both books and TV. What is the probability that a
person will be entertained by either books or TV?
A) 0.30
B) 0.70
C) 1
D) 0.40
E) 0.22
3) Find the median for the following data set:
15
18
A) 8
15
23
B) 15
3)
17
C) 17
D) 17.6
4) Out of 829 items checked out of a public library, 282 were fiction books, 294 were
non-fiction books, and 253 were videos (of any genre). What is the probability that a
randomly-selected item was not a video?
A) 0.439
B) 0.305
C) 0.695
D) 0.340
4)
5) The table below lists the populations, in thousands, of several rural western counties.
What is the mean population?
5)
County Population (thousands)
Aldridge
15
Cleveland
23
McCarthy
11
Pope
18
Sorrell
14
Wilson
8
A) 15 thousand
C) 14.8 thousand
B) 14.5 thousand
D) 15.5 thousand
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6) Find the population standard deviation for the following data set:
6)
21 12 20 15 18
A) 3.7
B) 3.3
C) 11
D) 13.7
7) For the data set below, list the outliers, if any.
A) 7
C) 7 and 92
7)
B) 7 and 20
D) There are no outliers.
8) A consumer advocacy group tested the "on-air" lifetimes a random sample of 162 cell
phone batteries. The mean lifetime was 2.9 hours with a standard deviation of 0.4
hours. The lifetimes are approximately bell-shaped. Estimate the number of batteries
with lifetimes between 2.1 hours and 3.7 hours.
A) 154
B) 8
C) 110
D) almost all (greater than 154)
8)
9) Gina and Stewart are surf-fishing on the Atlantic coast, where both bluefish and
pompano are common catches. The mean length of a bluefish is 261 millimeters with a
standard deviation of 45 mm. For pompano, the mean is 156 mm with a standard
deviation of 24 mm.
9)
Stewart caught a bluefish that was 286 mm long, and Gina caught a pompano that was
181 mm long. Who caught the longer fish, relative to fish of the same species?
A) Neither. Relative to its respective species, the fish are the same length.
B) Stewart
C) Gina
10) A student has an average of 88 on seven chapter tests. If the student's scores on six of
the tests are 91, 91, 92, 82, 91, and 70, what was the score on the remaining test?
A) 81
B) 88
C) 99
D) 86
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10)
11) A data set has a median of 43, and four of the numbers in the data set are less than
median. The data set contains a total of n numbers.
11)
If n is even, and none of the numbers in the data set is equal to 43, what is the value of
n?
A) 8
B) 6
C) 9
D) 12
12) The following population parameters were obtained from a graphing calculator.
12)
x=66
∑x=858
∑x2=56628
Sx=6.244998
σx=6
↓n=13
Assuming the population is bell-shaped, between what two values will approximately
68% of the population be?
A) 66 to 84
B) 60 to 72
C) 48 to 84
D) 54 to 78
13) In a poll of 724 university students, 311 said that they were opposed to legalizing
marijuana. Estimate the percentage of students who oppose legalizing marijuana.
A) 57%
B) 75.3%
C) 24.7%
D) 43%
13)
14) A 12-sided die can be made from a geometric solid called a
dodecahedron. Assume that a fair dodecahedron is rolled.
14)
The sample space is {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}.
Find P(Greater than 8).
A) 1/4
B) 1/12
C) 1/3
D) 7/12
15) Find the population variance for the following data set:
15)
13 23 26 17 21
A) 5.1
B) 26
C) 13
3
D) 20.8
16) There are 29,735 undergraduate students enrolled at a certain university. The age
distribution
is as follows:
16)
Age Range Number
13 - 14
5
15 - 17
280
18 - 22
12,050
23 - 30
10,931
31 and up
6469
Total
29,735
What is the probability that a student is less than 18 years old?
A) 0.0096
B) 0.00017
C) 0.218
D) 0.0094
17) For the data set below, find the first quartile.
A) 61
17)
B) 63
C) 43.5
D) 76
18) If P(A) = 0.46, P(B) = 0.37, and P(A or B) = 0.61, are A and B mutually exclusive?
A) Yes
B) No
Determine whether the events are disjoint and give a reason.
19) At a California college, 23% of students speak Spanish, 5% speak French, and 3% speak both
languages. Are speaking Spanish and speaking French disjoint events?
A) Yes, a student cannot speak both Spanish and French at the same time
B) Yes, the probability that a student speaks French is the same as the probability that a
students speaks French given that they speak Spanish.
C) Yes, because P(S or F) = P(S) + P(F)
D) No, 3% of students speak both languages
E) No, the probability that a student speaks Spanish is 0.23%, but the probability that a
student speaks Spanish given that they speak French is 0.60.
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18)
19)
Answer Key
Testname: TEST 2B FALL 2016
1) D
2) D
3) C
4) C
5) C
6) B
7) C
8) A
9) C
10) C
11) A
12) B
13) D
14) C
15) D
16) A
17) B
18) B
19) D
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