Question number 1.
Your answer was A. Correct. Given the following sampling distribution:
X
-20
-14
-2
12
15
P(X)
1
/
50
3
/
50
1
/
25
1
/
25
___
What is P(X = 15)?
A
0.84
B
0.85
C
0.82
D
0.15
E
0.83
F
None of the above
Question number 2.
Your answer was C. Correct. Given the following sampling distribution:
X
-16
-11
-3
11
16
P(X)
1
/
20
3
/
100
1
/
20
9
/
100
___
What is P(X > -11)?
A
0.91
B
0.94
C
0.92
D
0.95
E
0.90
F
None of the above
Question number 3.
Your answer was A. Correct. Given the following sampling distribution:
X
-20
-9
-4
6
16
P(X)
2
/
25
9
/
100
9
/
100
1
/
20
___
What is the mean of this sampling distribution?
A
8.6
B
−
0.4
C
−
2.2
D
8.7
E
8.3
F
None of the above
Question number 4.
Your answer was D. Correct. Suppose you have a distribution, X, with mean = 13 and standard deviation = 3. Define a new random variable Y = 4X - 5. Find the mean and standard deviation of Y.
A
E[Y] = 52; σ
Y
= 7
B
E[Y] = 47; σ
Y
= 48
C
E[Y] = 52; σ
Y
= 48
D
E[Y] = 47; σ
Y
= 12
E
E[Y] = 47; σ
Y
= 7
F
None of the above
Question number 5.
Your answer was E. Correct. In testing a certain kind of missile, target accuracy is measured by the average distance X (from the target) at which the missile explodes. The distance X is measured in miles and
the sampling distribution of X is given by:
X
0
10
50
100
P(X)
1
/
8
1
/
4
1
/
2
1
/
8
Calculate the mean of this sampling distribution.
A
37.5
B
30.4
C
41.5
D
925.0
E
40.0
F
None of the above
Question number 6.
Your answer was B. Correct. In testing a certain kind of missile, target accuracy is measured by the average distance X (from the target) at which the missile explodes. The distance X is measured in miles and
the sampling distribution of X is given by:
X
0
10
50
100
P(X)
1
/
12
1
/
6
1
/
3
5
/
12
Calculate the variance of this sampling distribution.
A
37.6
B
1416.7
C
2600.0
D
472.2
E
60.0
F
None of the above
Question number 7.
Your answer was B. Correct. Suppose you want to play a carnival game that costs 8 dollars each time you play. If you win, you get $ 100. The probability of winning is 3
/
100
. What is the expected value of the
amount the carnival stands to gain?
A
5.10
B
5.00
C
5.30
D
−
5.00
E
3.00
F
None of the above
Question number 8.
Your answer was E. Correct. Suppose you want to play a carnival game that costs 5 dollars each time you play. If you win, you get $ 100. The probability of winning is 1
/
100
. What is the expected value of the
amount that you, the player, stand to gain?
A
−
3.90
B
−
1.00
C
−
4.10
D
4.00
E
−
4.00
F
None of the above
Question number 9.
Your answer was E. Correct. A random sample of 2 measurements is taken from the following population of values: -1, 0, 2, 3, 6. What is the probability that the range of the sample is 2?
A
0.3
B
0.5
C
0.2
D
0.4
E
0.1
F
None of the above
Question number 10.
Your answer was B. Correct. A furniture store is having a sale on sofas and you're going to buy one. The advertisers know that buyers get to the store and that 1 out of 4 buyers change to a more expensive sofa
than the one in the sale advertisement. Let X be the cost of the sofa. What is the average cost of a sofa if the advertised sofa is $ 100 and the more expensive sofa is $ 375?
A
306.25
B
168.75
C
168.64
D
237.50
E
155.00
F
None of the above
