A hypothesis is best defined as
Answer
a difficult to define question
an educated guess
cause and effect analysis
a scientific inquiry
10 points
Question 2
The following hypothesis is an example of what type of hypothesis: The mean annual
cost to house inmates in the West is equal to the mean cost in the Northwest.
Answer
the positively skewed hypothesis
the nondirectional research hypothesisthe directional research hypothesis
the null hypothesis
10 points
Question 3
Which of the following statements is the best example of a traditional research
hypothesis?
Answer
There is no relationship between fatigue and reaction time.
The heart rate of individuals engaged in aerobic exercise for 20 minutes will be
higher than individuals who have been resting for 20 minutes.
Slippery roads do not cause accidents.
There is no difference between tuition assistance available to families with an
income of $25,000 and families with an income of $40,000.
10 points
Question 4
A ____________ test reflects a ______________ hypothesis.
Answer
one-tailed / nondirectional
one-tailed / directional
two-tailed / directional
two-tailed / null
10 points
Question 5
Calculate the z scores for a distribution with a mean of 150 and a standard deviation of 15
for the following raw scores: Formula: Answer
135 z score = -5.8
140 z score = -0.67
170 z score = -3.33
185 z score = -2.33
10 points
Question 6
If a normal distribution has a mean of 35 and a standard deviation of 5, what value would
be +1.5 standard deviations from the mean?
Answer
40
42.5
27.5
30
10 points
Question 7
What z score is associated with a raw score of 240 in distribution with a mean of 200 and
a standard deviation of 25?
Answer
z = .4
z = -.4
z = 1.6
z = -1.6
10 points
Question 8 If a z score = 2.5, it is _____ standard deviations above the mean.
Answer
1
-2.5
3
2.5
10 points
Question 9
For this problem, make sure you read pages 151-154, especially 153
What is the area between a raw score of 113 and 126 in a normal distribution with a mean
of 100 and a standard deviation of 100?
Steps:
1. z score for 113 = .13
2. z score for 126 = .26
3. the area between the mean and z score of .13 = 5.17
4. the area between the mean and z score of .26 = 10.26
5. 10.26 – 5.17 = XXXX (percent of the distribution)
Answer
11.95% of the distribution
-5.09% of the distribution
110% of the distribution
5.09% of the distribution
10 points
Question 10
Standard scores are comparable because
Answer
they come from the same sample
they are standardized in units of standard deviations
they have the same distribution means
they are not comparable
1.
the hypothesized reason.
Answer
100
5
25
20
10 points
Question 2
1.
A(n) ____________ difference is due to some systematic influence and not due to
chance.
Answer significant
insignificant
null
serendipitous
10 points
Question 3
1.
For a one-tail positive test, if the obtained value falls to the right of the critical value, you
should conclude:
Answer
reject the null
retain the null
there is an error in your data
there is an error in your calculations
10 points
Question 4
1.
If you reject a null hypothesis and (in reality) there is no difference between two groups,
then you have
Answer
made a Type I error
made a Type II error
made a Type III error
not made an error at all
10 points Question 5
1.
If you accept the null hypothesis and (in reality) there is a difference between two groups,
then you have
Answer
made a Type I error
made a Type II error
made a Type III error
not made an error at all
10 points
Question 6
1.
If you accept the null hypothesis and (in reality) there is no difference between two
groups, then you have
Answer
made a Type I error
made a Type II error
made a Type III error
not made an error
10 points
Question 7
1.
If you reject the null hypothesis and (in reality) there is a difference between two groups,
then you have
Answer made a Type I error
made a Type II error
made a Type III error
not made an error
10 points
Question 8
1.
The degree of risk you are willing to take that you will reject a null hypothesis when it is
actually true is called
Answer
experimental error
significance level
error level
experimental level
10 points
Question 9
1.
As the size of your sample _______________ , the risk for a _______________ .
Answer
decreases / Type I error stays constant
increases / Type I error decreases and type II error increases
decreases / Type II error decreases
increases / Type II error decreases
10 points
Question 10
1.
Another name for the test statistic value is
Answer
Post-test value
beta test value
inferred value
obtained value
