ANSWERS
A researcher uses a survey to investigate the texting habits of adolescents in
Oregon. The entire group of adolescents who live in Oregon is an example of a
_________.
Population? Sample? Statistic? Parameter? - ANSWER-Population
A researcher uses an anonymous survey to investigate the study habits of American
college students. Based on the set of 300 surveys that were completed and returned,
the researcher finds that these students spend an average of 4.1 hours each week
working on course material outside of class. For this study, the numerical average of
4.1 hours is an example of a ____.
Population? Sample? Statistic? Parameter? - ANSWER-Statistic
In an experiment examining the effects of yoga training on anxiety, a researcher
recruits a sample of adults seeking treatment for anxiety symptoms. Half of the
participants are assigned to a yoga program and the other half (the control group)
waits 8 weeks before beginning the program. At the end of 8 weeks, participants
report their levels of anxiety. In this study, the independent variable is
_________________.
Yoga Training? Time (8 weeks)? Anxiety Levels? - ANSWER-Yoga Training
A researcher varies the loudness of a buzzer and measures how quickly young and
old subjects respond to it. In this study, age group is the _______________.
Independent Variable? Quasi-independent Variable? Dependent Variable? -
ANSWER-Quasi-Independent
Organizing a set of scores into a table or a graph would be an example of using
_____.
Sample Statistics? Descriptive Statistics? Inferential Statistics? - ANSWER-
Descriptive Statistics
Using sample data to answer general questions about a population is called ____.
Sample Statistics? Descriptive Statistics? Inferential Statistics? - ANSWER-
Inferential Statistics
Students in an introductory art class are classified as art majors and non-art majors.
If these values are presented in a frequency distribution graph, what kind of graph
would be appropriate?
Histogram? Bar Graph? - ANSWER-Bar Graph
It is possible to get 0 to 100 points in an exam. If these values are presented in a
frequency distribution graph, what kind of graph would be appropriate?
Histogram? Bar Graph? - ANSWER-Histogram
In general, what is the relationship between the standard deviation and variance?
,A) Variance is the square root of the standard deviation.
B) Standard Deviation is the square root of variance. - ANSWER-Standard Deviation
is the square root of variance.
Which of the following statements cannot be true for a distribution of scores?
70% of the scores are above the mean? 70% of the scores are above the median?
70% of the score are above the mode? - ANSWER-70% of the scores are above the
median.
Under what circumstances is the median likely to produce a better measure of
central tendency than the mean?
With a symmetrical distribution? With an extremely skewed distribution? When the
data consists of categorical measurements? - ANSWER-With an extremely skewed
distribution.
What is the most likely shape for a distribution with a mean of 50 and a median of
40?
Symmetrical? Positively Skewed? Negatively Skewed? - ANSWER-Positively
Skewed
A researcher asks participants to report their favorite movie genre. Which measure
of central tendency would be appropriate to summarize the measurements?
Mean? Median? Mode? - ANSWER-Mode
The students in a biology class seemed to think that the midterm exam was very
easy. If they are correct, what is the most likely shape for the distribution of exam
scores?
Symmetrical? Positively Skewed? Negatively Skewed? - ANSWER-Negatively
Skewed
Under what circumstances is a score that is 10 points above the mean an extreme
score relatively far from the mean?
When the population mean is much larger than 10? When the population standard
deviation is much larger than 10? When the population standard deviation is much
smaller than 10? - ANSWER-When the population standard deviation is much
smaller than 10
Which of the following z-scores represents the location farthest from the mean?
z=-1.00? z= 1.00? z=-2.00? - ANSWER--2.00
If an entire population with µ = 60 and σ = 8 is transformed into z-scores, then the
distribution of z-scores will have a mean of ____ and a standard deviation of ____.
60 and 8? 0 and 1? 0 and 8? - ANSWER-0 and 1
What position in the distribution corresponds to a z-score of z = -1.00?
Below the mean by 1 point?
Above the mean by 1 point?
Below the mean by a distance equal to 1 standard deviation?
Above the mean by a distance equal to 1 standard deviation? - ANSWER-Below the
mean by a distance equal to 1 standard deviation.
, Samples ______________ population variability.
Underestimate? Overestimate? Perfectly Reflect? - ANSWER-Underestimate
If you have a score of X = 80 on an exam with µ = 70, you should consider it a better
grade if:
σ = 5? σ = 10? σ = 15? - ANSWER-σ = 5
Which of the following statements is correct?
a. In a random sample, every individual must have an equal chance of being
selected. b. In a random sample, there must be sampling with replacement. c. Both
(a) and (b) are correct. - ANSWER-Both a and b are correct
With = 0.05, how are the boundaries for the critical region determined for a two-tailed
test?
a) Boundaries are drawn so there is 2.5% (.025) in each tail of the distribution.
b) Boundaries are drawn so there is 5% (.05) in each tail of the distribution.
c) Boundaries are drawn so there is 10% (.10) in each tail of the distribution -
ANSWER-Boundaries are drawn so there is 2.5% (.025) in each tail of the
distribution.
______________ is the standard difference between the sample mean (M) and one
randomly selected score (X) from that sample.
a. sample standard deviation
b. standard error
c. estimated standard error. - ANSWER-sample standard deviation
______________ is the standard difference between the population mean (µ) and
the mean of one randomly selected sample (M) from that population.
a. sample standard deviation
b. standard error
c. estimated standard error - ANSWER-standard error
Which of the following correctly describes the effect of decreasing the alpha level (for
example, from .05 to .01)?
a. Increase the likelihood of rejecting the null hypothesis and increase the risk of a
Type I error
b. Decrease the likelihood of rejecting the null hypothesis and increase the risk of a
Type I error
c. Decrease the likelihood of rejecting the null hypothesis and decrease the risk of a
Type 1 error - ANSWER-Decrease the likelihood of rejecting the null hypothesis and
decrease the risk of a Type 1 error
In a typical research situation, a _____________ means that the researcher
concludes that a treatment does have an effect when, in fact, it has no effect.
a. Type 1 error
b. Type 2 error - ANSWER-Type 1 error
A ______________ occurs when a researcher fails to reject a null hypothesis that is
really false.