Quiz 15
1.
The standard deviation of a binomial distribution is
a.
E(x) = P(I - P)
b. E(x) = nP
c. E(x) = nP(I - P)
d.
None of these alternatives is correct.
Answer: d
2.
The expected value for a binomial probability distribution is
a. E(x) = Pn(l - n)
b.

Quiz 22
1.
The ages of student s at a university are normally distributed with a mean of 2 I.
What percentage of the student body is at least 21 years old?
a. It could be any va lue, depending on the magnitude of the standard deviation b. 50%
c. 21%
d. 1.

Quiz 20
1.
Given that Z is a standard normal random variable , what is the probability that -2.51
a. 0.4950
b. 0.4370
c. 0.0570
d. 0.9310
Answer: c
2.
Given that Z is a standard normal random variable , what is the probability that
z
z
-2.12?
Answer: b
3.

Quiz 19
1.
A continuous random variable may assume
a.
b.
c.
d.
. all values in an interva l or collection of intervals
only integer values in an interval or collection of intervals
only fractiona l va lues in an interva l or collection of interva l s
all

Quiz 23
1.
A major department store has determined that its customers charge an average of
$500 per month , with a standard deviation of $80. Assume the amounts of charges are normally
distributed.
a. What percentage of customers charges more than $380 pe

Quiz 24
1.
A major department store has determined that its customers charge an average of
$500 per month , with a standard deviation of $80. Assume the amounts of charges are normally
distributed.
a. What percentage of customers charges more than $380 pe

Quiz 25
1.
In a no rm a l distributi o n, it i s known that 27.34% of all th e items are includ ed from 100 up t o
the mean, and another 45.99% of all the items are includ ed from the
mean up to 145. Determine t h e mean and the stand ard deviation of the

Quiz 26
1.
For a continuous random variable x, the probability density function tcfw_x) represents
a. the probability at a given value of x
b. the area under the curve at x
c. the area under the curve to the right of x
d. the height of the function at x
A

Quiz 27
1.
A continuous random variable may assume
a.
b.
c.
d.
. all values in an interva l or collection of intervals
only integer values in an interval or collection of intervals
only fractiona l va lues in an interva l or collection of interva l s
all

Quiz 18
1.
For a continuous random variable x, the probability density function tcfw_x) represents
a. the probability at a given value of x
b. the area under the curve at x
c. the area under the curve to the right of x
d. the height of the function at x
A

Quiz 31
1.
Given that Z is a standard normal random variable. What is the value of Z if the area to the
right of Z is 0.1401?
a. 1 .08
b. 0.1401
c. 2.16
d. -1.08
Answer: a
2.
Given that Z is a standard normal random variable. What is the va lue of Z if th

Quiz 28
Exhibit 6-3
Consider the continuous random variable X, which has a uniform distribution over the interval from 20
to 28.
1.
Refer to Exhibit 6-3. The probability density function has what value in the
interval between 20 and 28?
a. 0
b. 0.050
c. 0

Quiz 32
1.
The pri ce of a bond is uniformly distributed between $80 and $85.
a.
b.
c.
d.
What i s the probabilit y that the bond price will be at least $83?
What is the probability that the bond price will be between $81 to $90?
Determine the expected pr

Quiz 33
1.
The time it takes a worker on an assembly line to complete a task is exponentially distribut
ed with a mean of 8 minutes.
a. What is the probability density function for the time it takes to complete the task?
b. What is the probability that it

Quiz 30
1.
Given that Z is a standard normal random variable. What is the value of Z if the area to the
right of Z is 0.1401?
a. 1 .08
b. 0.1401
c. 2.16
d. -1.08
Answer: a
2.
Given that Z is a standard normal random variable. What is the va lue of Z if th

Quiz 29
Exhibit 6-7
The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a
standard deviation of 2 ounces.
1.
Refer to Exhibit 6-7. What is the probability that a randomly selected item will weigh
more than 10 ounc

Unit of Sales
From Case Exhibit 11 &
12
For Consoles
Parameters
First Year 2008
2nd Year 2009
3rd year 2010
Total Expected sales in 3 years
Year
1st Year 2008
2nd Year 2009
3rd year 2010
Total Units required to BEV
FOR BEV
For PC
Year
First Year 2008
2nd

Quiz 21
Exhibit 6-6
The starting salaries of individuals with an MBA degree are normally distributed with a mean of
$40,000 and a standard deviation of $5,000.
1.
Refer to Exhibit 6-6. What i s the probabi l ity that a randomly selected individual with an

Quiz 18
1.
For a continuous random variable x, the probability density function tcfw_x) represents
a. the probability at a given value of x
b. the area under the curve at x
c. the area under the curve to the right of x
d. the height of the function at x
A

Prob Stats Quiz 3
1.
2.
Th e collect ion of all elemen ts of interest in a particular study
is a . the popula tion
b.
t he sam pl ing
c. statistical inferen ce
d.
descriptive
statistics Answer :
a
A port ion of the popu lation selected to represen t the p

Prob Stats Quiz 2
1.
All the data collected in a particular study are referred t o as the
b.
c.
a.
inference
variable
data set
d.
Non e of these alternatives i s
correct . An swer: c
2.
Another name for "observations" is
a.
. views
b. variables
c. cases
d

Prob Stats Quiz 4
1.
The height of a building , measured in feet, i s an example of
a.
qualitative data
b. either qualitative or quantitative data
c. feet data
d.
quantitativ
e data Answer:
d
2.
An interviewer has made an error in recording the data. This

Prob Stats Quiz 5
1.
A frequency distri bu tion is a tabular sum mary of data sh owing th e
a. fraction of items in several classes
b. percentage of i t ems i n several classes
c. relat ive percen t age of items i n several
classes d. num ber of item s in

Prob Stats Quiz 6
Exhibit 2-1
The numbers of hours worked (per week) by 400 statistics students are shown below.
Number of hours
0- 9
10 - 19
20 - 29
30 - 39
Frequency
20
80
200
100
1.
Refer to Ex hibit 2-1. The class width for this distribution
a. i s 9

Quiz 7
I.
Which of the following provid es a mea sure of central location for the data?
a. standard deviation
b. mean
c. vanance
d. range
Answer: b
2.
When computing the mean of a set of values xi , the value of Ixi
a. can never be zero
b. can never be ne

Quiz 8
1.
The value which has half of the observat ions above it and half the observat
ions below it is called the
a. range
b. median
c. mean
d. mode
Answer: b
2.
The most frequently occurring va lue of a data set is called the
a. range
b. mode
c. mean
d.

Quiz 9
1.
The sample variance
a. is always smaller than the true value of the population variance
b. is always larger than the true valu e of the population variance
c. could be smaller , equal to , or larger than the true va lue of the population vanance

Quiz 10
1.
.
a.
b.
c.
d.
Th e
coefficient of correlation
is the same as the coefficient of determination
can be larger than 1
ca nnot be larger than I
cannot be negative
Answer: c
2.
The value of the sum of the deviations from the m ea n , i.e., I(x -x )

Quiz 11
Exhibit 3-3
A researcher has collected the following sample data. The mean of the sample is 5.
3
1.
5
12
3
2
Refer to Exhibit 3-3. The variance is
a. 80
4.062
b.
c. 13.2
d. 16.5
Answer: d
2.
Refer to Exhibit 3-3. The standard deviation i s a.
8.94

Quiz 12
1.
The average wage of Tennessee cashiers is $14 per hour with a standard devia tion of
$4.20. rn Georgia, the average wage of cashiers i s $I 6 with a stand ard deviation of $4.40. In
which state do the wages of cashiers appear to be more dispers