Stats for behavioral sciences Final
there are two values for trite when H1 is directional
False
The degrees of freedom for the t test for single samples are _________.
N-1
After several studies, Professor Smith concludes that there is a zero correlation between body weight and bad tempers. This means that _________.
a person with a bad temper may be heavy or skinny
A priori probability refers to _________.
a probability value deduced from reason alone
If the alternative hypothesis states that alcohol affects short-term memory, the null hypothesis states _________.
alcohol has no effect on the short term, memory
If H0 is true, then the probability of rejecting H0 is limited by _________.
alpha
Inferential statistics _________.
also uses methods of descriptive statistics and allows one to make inferences about a population based on sample data
In a positive relationship, _________.
as X increases, Y increases and as decreases, Y decreases
A nutritionist uses a scale that measures weight to the nearest 0.01 grams. A slice of cheese weighs 0.35 grams on the scale. The true weight of the cheese _________.
may be anywhere in the range 0.345-0.355 grams
The most commonly encountered measure of central tendency is the _________.
mean
In a bell-shaped distribution, _________.
mean=median
The t test assumes that the independent variable affects the _________ of the populations.
means
Consider the following scores: 21, 22, 22, 0.1, 20, 25, 28, 26, 23, 19, 0.5. Which of the measures listed below would give the best description of the central tendency of these scores?
median
Which method of knowing is used in the following example? An individual accepts as true that there is an afterlife because a minister asserts such is the case.
method of authority
Student's t test for correlated groups is _________.
more powerful than the sign test because it uses both the magnitude and direction of the scores
In stating H0 and H1, one must be certain that they are _________.
mutually exclusive and exhaustive
The df associated with evaluating the significance of robt are _________.
n-2
In the t test for independent samples, there are _________ degrees of freedom.
n1+n2-2
A distribution has a mean of 78 and a median of 92. This distribution is _________.
negatively skewed
If a distribution of raw scores is negatively skewed, transforming the raw scores into z scores will result in a _________ distribution.
negatively skewed
"Brand of soft drink" is measured on a(n) _________.
nominal scale
The z test for independent groups is seldom used because _________
we seldom know the population variances
The advantage of a powerful experiment is that _________.
you are more likely to detect the real effects of the independent variable, if there are any
Using the z test with alpha= 0.052 tail, the appropriate critical value is
zcrit= +/-1.96
We can reject H0 if _________.
| zobt | ≥ | zcrit |
If H0 is in reality false and it is legitimate to use a directional H1, which of the following will yield a more powerful test?
one-tailed alternative hypothesis
The binomial distribution is symmetrical _________.
only when P=Q=.50
If a large psychology class took a test on theoretical biophysics, the distribution of scores would probably be _________.
positively skewed
If the null hypothesis is false, the probability of making a correct decision is given by _________.
power
A discrete scale of measurement _________.
provides exact measurements
The critical value for the z distribution using α = 0.052 tail is _________.
+/- 1.96
If we take all possible samples from a normally distributed population, which of the following sample sizes will yield the smallest variation in the means of the samples?
120
A true-false test of 20 questions is given to 10,000 students. If all the students guess on each question, how many students would you expect to get 17 or more questions correct?
13
Y can be most accurately predicted from X if the correlation between X and Y is _________.
-0.98
The correlation coefficient between heights from the ground of two people on the opposite ends of a seesaw would be _________.
-1.0
If A and B are mutually exclusive and exhaustive, then p(A and B) = _________.
0
In a correlated t test, if the independent variable has no effect, the sample difference scores are a random sample from a population where the mean difference score (µD) equals _________
0
The mean of the t distribution equals _________.
0
The z score corresponding to the mean of a raw score distribution equals _________.
0
Probabilities vary between __________.
0 and 1
Assuming the binomial distribution is appropriate, if N = 12 and P= 0.60, the probability of getting exactly 11 P events is _________.
0.0174
If the correlation between exposure to violence on TV and aggressive behavior by children is r=0.20, what proportion of variance in aggressive behavior can be accounted for my knowing how much violence on TV a child has been exposed to?
0.02
Suppose you flip 35 biased coins once. The probability of a head with each coin equals 0.30. What is the probability you will get 15 or more heads?
0.0485
Assuming the binomial distribution is appropriate, if N = 6 and P = 0.50, the probability of getting exactly 5 P events = _________.
0.0938
The lowest degree (i.e., strength) of correlation shown below is _________.
0.15
The lowest degree of correlation shown below is _________.
0.15
The probability of drawing a face card (king, queen or jack) of any suit from a deck of 52 ordinary playing cards in one draw is _________.
0.231
A football player is practicing making field goals from the 30-yard line. If the probability of his kicking a field goal is 0.75, what is the probability he will kick at least 12 field goals in the next 15 tries? Assume independence between tries.
0.4613
The proportion of scores less than z = 0.00 is _________.
0.50
If 49% of the total variability of Y is accounted for by X, what is the value of r?
0.70
The standard deviation of the z distribution equals _________.
1
If the correlation between two variables is −1.00 and the score of a given individual is 2.20 standard deviations above the mean on one of the variables, we would predict a score on the second variable of _________.
2.20 standard deviations below the mean
The mean number of students in a classroom at school A is 32.5 and there are 25 classrooms. The mean number of students at school B is 29.6 in 12 classrooms. At school C the mean in each class is 15.3 for 10 classrooms. What is the mean number of students per classroom for all the schools combined?
28.1
Given the following set of numbers, X1 = 2, X2 = 4, X3 = 6, X4 = 10,what is the value of (Σ X)2?
484
After performing several clever calculations on your calculator, the display shows the answer 53.655001. What is the appropriate value rounded to two decimal places?
53.66
A distribution has a mean of 60.0 and a standard deviation of 4.3. The raw score corresponding to a z score of 0.00 is _________.
60.0
In a normal distribution approximately _________ of the scores will fall within 1 standard deviation of the mean.
70%
In a situation where there are only two possible events, A and B, on each trial, if P = Q oneach trial
A and B must be mutually exclusive
if you retain the null hypothesis, you may be making
Type II error and/or a correct decision
In order to use the binomial distribution, which of the following conditions are necessary?
a series of N trials with only 2 possible outcomes, outcomes are mutually exclusive; there must be independence between trials; P and Q must remain the same from trial to trial
if you reject the null hypothesis, you may be making ___________
a type I error and a correct decision
An accountant is preparing a graph showing the number of sports cars of various makers purchased this year. The number will be plotted on the ordinate and the various manufacturers on the abscissa. The proper type of graph for this data is a(n) _________.
bar graph
As N increases, the binomial distribution _________.
becomes more normally distributed
If you reject H0 when H0 is false, you have made a _________.
correct decision
correlation and regression differ in that ___________
correlation is concerned with prediction and regression is concerned with causation
Which of the following words describe the type of learning that takes place inside of the classroom of flipped classes (select all that apply):
create, analyze
Which of the following is (are) major advantage(s) of a two condition experiment over a single sample design? Select all that apply.
creates ability to control for other variables which may affect the results; no need to know any parameters of the raw score population; a lack of dependence on population values which may be inappropriate
In order to estimate the amount of TV watched by New York City adults, a sociologist surveys a random sample of adults from this city. The obtained raw scores are called _________.
data
Let's assume you are conducting an experiment to determine the effect of a new drug on the incidence of epileptic seizures. You select 20 epileptics from the 150 epileptics being treated at a nearby hospital and administer the drug to them. You record the number of seizures in each of the 20 subjects for one month. Incidence of seizures is an example of a(n) _________.
dependent variable
The sampling distribution of t depends on _________.
df
In the repeated measures design, _________.
differences between paired scores are analyzed
often, students ______________ flipped classrooms.
do not like, get higher grades in, feel that more work is required In, learn more in
If the population parameters are known, the t test is _________ powerful than the z test.
less
The t test is _________ likely to result in a Type II error than the sign test for a repeated measures design.
less
For any given obtained result, a one tailed p-level is
less than the two tail p-level and is appropriate to use only if the alternative hypothesis is directional
The binomial distribution _________.
gives each possible outcome of N trials
| tcrit | for any alpha level is _________ | zcrit | for N less than infinity
greater than
| tcrit | for any alpha level is _________ | zcrit | for N less than infinity.
greater than
if the correlation between variables X and Y is 0.95, which of the following is true
high scores on X are accompanied by high scores on Y
The closer the points on a scatter diagram fall to the regression line, the _________ between the scores.
higher the correlation
The closer the points on a scatter plot fall to the regression line, the _________ between the scores.
higher the correlation
an alpha level of 0.05 indicates that
if H0 is true, the probability of falsely rejecting it is limited to 0.05
In traditional classrooms students are first exposed to the to-be learned material ____________; in a flipped class first exposure occurs ____________.
in class; outside of class
Which of the following increase(s) the power of the t test? (select all that apply)
increasing N, increasing the effect of the independent variable
Which of the following is(are) correct interpretation(s) of correlation? Correlation _________.
indicates the degree of the relationship between two variables; is useful in deciding which variables to manipulate in an experimental study
For the z test, the critical region for rejection of H0 _________.
is determine only by alpha
The alpha level _________.
is determined by the consequences of making a Type I and Type II error
the alpha level _______
is determined by the consequences of making a Type I and Type II error
For the z test, the critical region for rejection of H0 _________.
is determined only by alpha
Two events are mutually exclusive if __________.
the both cannot occur together
Reaction time in seconds is an example of a(n) _________ scale.
ration
If alpha equals 0.05 and the probability level obtained (pobt) in your experiment is 0.04, you would _________.
reject the null hypothesis
What indicates the proportion of the total number of scores that occurred in each interval?
relative frequency distribution
With which statistical test do we determine the probability of getting the obtained results or those more extreme assuming the differences in results were due to chance alone?
sign test, z test, t test
Assume that the standard deviation of one distribution equals 15 and the standard deviation of another distribution is equal to 23. Which of the following distributions is more likely to represent the case where s = 15 if the other distribution's standard deviation equals 23?
slimmer tall graph
The most commonly encountered measure of variability is _________.
standard deviation
In order to estimate the height of all students at your university, let's assume you have measured the height of all psychology majors at the university. The average (mean) value of the measured height scores constitutes a _________.
statistic
The Null Hypothesis Population is an actual or theoretical set of population scores that would result if _________.
the experiment were done on the entire population and the independent variable had no effect
The nondirectional alternative hypothesis asserts that _________.
the independent variable has an effect
"Degrees of freedom" for any statistic is defined as _________.
the number of scores that a re free to vary in calculating the statistic
Two events are independent if ____________.
the occurrence of one has no effect on the probability of occurrence of the other
lf alpha is changed from 0.05 to 0.01, _________.
the probability we will retain a false H0 increases
If the result of an experiment is statistically significant, this means _________.
the result is reliable and if we repeat the experiment, we expect the result to be significant again
If the result of an experiment is statistically significant, this means ___________.
the result is reliable and if we repeat the experiment, we expect the result to be significant again
A set of events is exhaustive if __________.
the set includes all of the possible events
If one draws all possible samples for various values of N from the same population of raw scores, as N increases _________.
the standard error of the mean decreases
For the binomial distribution to be applicable to a situation,
the value P and Q must be the same from trial-to-trial
Two events are mutually exclusive if _________.
they both cannot occur together
A correlation between college entrance exam grades and scholastic achievement was found to be −1.08. On the basis of this you would tell the university that _________
they should hire a new statistician
A z score designates how many standard deviations the raw score is above or below the mean.
true
It is possible to have more than one mode in a sample of scores.
true
The median and the 50th percentile rank score will always have the same value.
true
To use the z test, µ and σ must be specified.
true
From which of the following studies can one most reasonably determine cause and effect?
true experiment