Test yourself on these multiple-choice questions. Clicking on the letter of your choice will give you immediate feedback on whether you are correct. Even when you are incorrect, you will receive feedback that will help you learn the material better so that you do well on the exam.
Which of the following is NOT a
descriptive statistic?
(a) t-test
(b) mean
(c) standard deviation
(d) range
The purpose of descriptive
statistics is to
(a) determine if the sample data accurately describe the
population.
(b) simplify and organize large sets of data.
(c) help us decide whether population means are equal.
(d) all of the above
Which of the following measures of
central tendency can have more than one value in a single
sample?
(a) mean
(b) median
(c) mode
(d) none of the above
Which of the following measures of
central tendency could be computed on a variable that is
measured on a nominal scale of measurement?
(a) mean
(b) median
(c) mode
(d) all of the above
Which of the following descriptive
statistical procedures CANNOT be used with a continuous
variable?
(a) a frequency distribution
(b) a grouped frequency distribution
(c) a median
(d) a mean
If a frequency polygon showed a
distinctive bunching of scores near the bottom of the scale with
just a few scores in the middle and upper parts of a scale, we
would say that the data were
(a) normally distributed.
(b) positively skewed.
(c) negatively skewed.
(d) symmetric.
A normal curve is
(a) positively skewed.
(b) negatively skewed.
(c) symmetric.
(d) bimodal.
Which measure of variability could
remain unchanged if one score in the sample decreased by 10
points?
(a) range
(b) variance
(c) standard deviation
(d) All of these measure would always change if one score
were changed.
For the data illustrated in the
scatter plot below, what is the product-moment correlation?
(a) 0.00
(b) +1.00
(c) -1.00
(d) You cannot tell from the scatter plot.
If you wanted to quantify the
degree of relationship between academic achievement and
creativity, which correlation coefficient would you want to use?
(a) Pearson product-moment correlation
(b) Spearman rank-order correlation
(c) Either would be appropriate.
(d) It would depend on how the variables were measured.
Which term refers to the
sensitivity of a statistical procedure?
(a) statistical reliability
(b) validity or statistical validity
(c) statistical replication
(d) power or statistical power
Which technique would be most
sensitive to (i.e., would help you identify) a nonlinear
relationship?
(a) the Pearson product-moment correlation
(b) the Spearman rank-order correlation
(c) a scatter plot
(d) a t-test
Which correlation represents the
strongest relationship?
(a) +.37
(b) +.68
(c) -.02
(d) -.73
If alpha is set to .05, what will
the level of Type II error be?
(a) .05
(b) .95
(c) 0
(d) cannot say
What will happen if the researcher
increases the level of Type I error without making any other
changes?
(a) The level of Type II error will increase.
(b) The level of Type II error will decrease.
(c) Alpha will decrease.
(d) There will be no change in either alpha or the level of
Type II error.
If two populations are different on
their population means and the inferential statistical test
leads you to conclude that the populations are equivalent, you
have
(a) made a Type I error.
(b) made a Type II error.
(c) drawn a correct inference.
(d) inflated your alpha.
The distinction between the average
deviation and the variance is
(a) the average deviation is the square root of the
variance.
(b) the average deviation is the average distance each score
is from the mean whereas the variance in the average squared
distance each score is from the mean.
(c) the average deviation is the square of the variance.
(d) the variance is the square of the standard deviation,
which is equal to .707 times the average deviation.