1
A linear regression:
gives a relationship between three variables that can be described by a line
gives a relationship between two variables that cannot be described by a line
contains only two variables
gives a relationship between two variables that can be described by a line
2
In a hypothesis test, a Type I error occurs when:
a false null hypothesis is rejected
a false null hypothesis is not rejected
a true null hypothesis is rejected
a true null hypothesis is not rejected
3
For small degrees of freedom, the chi-square distribution is:
skewed to the right
symmetric
skewed to the left
rectangular
4
What is the critical value of t for the hypothesis test?
2.441
2.733
2.449
2.738
5
A quantitative variable is the only type of variable that can:
have no intermediate values
assume numeric values for which arithmetic operations make sense
be used to prepare tables
be graphed
6
The alternative hypothesis is a claim about a:
parameter, where the claim is assumed to be true if the null hypothesis is declared false
parameter, where the claim is assumed to be true until it is declared false
statistic, where the claim is assumed to be true if the null hypothesis is declared false
statistic, where the claim is assumed to be false until it is declared true
7
Which of the following pairs of events are mutually exclusive?
Female and no
No and yes
Female and male
Female and yes
8
For a goodness-of-fit test, the frequencies obtained from the performance of an experiment are the:
objective frequencies
observed frequencies
expected frequencies
subjective frequencies
9
You toss a coin nine times and observe 3 heads and 6 tails. This event is a:
multinomial sample point
simple event
compound event
multiple outcome
10
Two paired or matched samples would imply that:
two data values are collected from the same source (elements) for two independent samples
two data values are collected from the same source (elements) for two dependent samples
data are collected on two variables from the elements of two independent samples
data are collected on one variable from the elements of two independent samples
11
The model y = A + Bx is a:
nonlinear model
probabilistic model
deterministic model
stochastic model
12
An error that occurs because of chance is called:
nonsampling error
probability error
sampling error
mean error
13
To make tests of hypotheses about more than two population means, we use the:
analysis of variance distribution
normal distribution
chi-square distribution
t distribution
14
The regression model y = A + Bx + e is:
a probabilistic model
a deterministic model
an exact relationship
a nonlinear model
15
A qualitative variable is the only type of variable that:
cannot be graphed
can assume an uncountable set of values
can assume numerical values
cannot be measured numerically
16
A researcher wants to test if the mean annual salary of all lawyers in a city is different than $110,000. The null hypothesis for this example will be that the population mean is:
less than to $110,000
greater than to $110,000
equal to $110,000
not equal to $110,000
17
The mean of a discrete random variable is the mean of its:
frequency distribution
second and third quartiles
percentage distribution
probability distribution
18
The graph of a cumulative frequency distribution is a(n):
ogive
frequency histogram
stem-and-leaf display
line graph
18
The graph of a cumulative frequency distribution is a(n):
ogive
frequency histogram
stem-and-leaf display
line graph
19
In a hypothesis test, a Type II error occurs when:
a true null hypothesis is rejected
a true null hypothesis is not rejected
a false null hypothesis is not rejected
a false null hypothesis is rejected
20
For a one-tailed test, the p-value is:
the area under the curve to the same side of the value of the sample statistic as is specified in the alternative hypothesis
twice the area under the curve between the mean and the observed value of the sample statistic
the area under the curve between the mean and the observed value of the sample statistic
twice the area under the curve to the same side of the value of the sample statistic as is specified in the alternative hypothesis
21
We can use the analysis of variance procedure to test hypotheses about:
two or more population means
the proportion of one population
the mean of one population
two or more population proportions
22
The p-value is the:
smallest significance level at which the null hypothesis can be rejected
smallest significance level at which the null hypothesis can be rejected
largest significance level at which the null hypothesis can be rejected
largest significance level at which the alternative hypothesis can be rejected
23
If you divide the number of elements in a sample with a specific characteristic by the total number of elements in the sample, the dividend is the:
sample proportion
sample distribution
sampling distribution
sample mean
24
In a one-way ANOVA, we analyze only one:
variable
population
sample
mean
25
The mean of a discrete random variable is its:
upper hinge
second quartile
box-and-whisker measure
expected value
26
You randomly select two households and observe whether or not they own a telephone answering machine. Which of the following is a simple event?
At least one of them owns a telephone answering machine.
Exactly one of them owns a telephone answering machine.
At most one of them owns a telephone answering machine.
Neither of the two owns a telephone answering machine.
27
A researcher wants to test if elementary school children spend less than 30 minutes per day on homework. The alternative hypothesis for this example will be that the population mean is:
not equal to 30 minutes
equal to 30 minutes
less than or equal to 30 minutes
less than 30 minutes
28
A continuous random variable x has a right-skewed distribution with a mean of 80 and a standard deviation of 12. The sampling distribution of the sample mean for a sample of 50 elements taken from this population is:
skewed to the right
not normal
approximately normal
skewed to the left
29
Which of the following assumptions is not required to use ANOVA?
The samples drawn from different populations are random and independent.
The populations from which the samples are drawn have the same variance.
The populations from which the samples are drawn are (approximately) normally distributed.
All samples are of the same size.
30
What is the critical value of z for the hypothesis test?
-2.05
-2.17
-2.33
-1.96.