Statistical Methods Final Exam
false
True or False- The t distribution is the same for all sample sizes.
true
True or False- The t test for correlated groups is just like the t test for single samples except that it analyzes difference scores.
false
True or False- The t test for single samples is used when the population parameter µ is unknown.
true
True or False- The variance is the square of the standard deviation.
false
True or False- When a sampled score is put back in the population before selecting the next score, this process is called sampling without replacement
false
True or False- When calculating the population standard deviation, we use N - 1 in the denominator.
false
True or False- A significant Fobt value indicates that all the group means are significantly different from each other.
true
True or False- A value of -1.0 for Fobt is never possible if the calculations are done correctly.
true
True or False- Fobt = (SSbetween/dfbetween)/(SSwithin/dfwithin)
false
True or False- Fobt = MSwithin/MSbetween
false
True or False- Hypothesis testing is part of inferential statistics while parameter estimation is used in descriptive statistics.
true
True or False- If F < 1, the independent variable has not had a significant effect.
true
True or False- If F < 1.0 we don't even have to bother to look up Fcrit since the result cannot possibly be significant.
false
True or False- If Fobt < Fcrit, we reject H0.
false
True or False- If Fobt is significant, it is possible to tell which groups differ from which without further analysis.
true
True or False- If one uses N instead of N - 1 in the denominator of the equation for the sample standard deviation, one will underestimate the population standard deviation.
false
True or False- If the raw score distribution is very positively skewed, the standard deviation of the z transformed scores will not equal 1.
true
True or False- In a positively skewed distribution, the mean has a higher value than the median.
false
True or False- In a skewed distribution, the mean and median are equal.
false
True or False- It is impossible to have a z score of 23.5.
false
True or False- Probability values range from -1.00 to +1.00.
true
True or False- SStotal = SSwithin + SSbetween
true
True or False- The F distribution has no negative values.
true
True or False- The addition rule is concerned with determining the probability of A or B, while the multiplication rule is concerned with determining the probability A and B.
false
True or False- The alternative hypothesis in an ANOVA can be either directional or nondirectional.
true
True or False- The area beyond a z score of +2.58 is 0.005.
true
True or False- The degrees of freedom equal N - 1 for the t test for single samples.
false
True or False- The dependent variable is the variable that is systematically manipulated.
false
True or False- The median is most affected by unbalanced extreme scores
true
True or False- The normal curve never touches the X axis.
true
True or False- The range is equal to the highest score minus the lowest score.
true
True or False- The symbol SS stands for sum of squares.
true
True or False- The t distribution is a family of curves that vary with the degrees of freedom.
nominal scale
"Brand of soft drink" is measured on a -----------
can take an infinite number of intermediate possible values
A continuous scale of measurement is different than a discrete scale in that a continuous scale _________.
negatively skewed
A distribution has a mean of 78 and a median of 92. This distribution is _________.
minimizes type II errors but increases type I errors
A liberal statistical test is one that
is a graph of paired X and Y values
A scatter plot _________.
two independent variables; three independent variables
A two-way ANOVA has _____ and a three-way ANOVA has _____.
statistical significance
An observed difference between two descriptive statistics that is unlikely to have occurred by chance represents
ordinal scale
At the annual sailing regatta, prizes are awarded for 1st, 2nd, 3rd, 4th, and 5th place. These "places" comprise --------
nominal
Classifying subjects on the basis of sex is an example of using what kind of scale?
null; alternative
Concluding there is no effect of the independent variable is to the _____ hypothesis, as concluding there is an effect of the independent variable is to the _____ hypothesis.
correlation is primarily concerned with the size and direction of relationships and regression is primarily used for prediction
Correlation and regression differ in that _________.
Type II
Failing to reject H0 when we should have rejected it is a _____ error.
true experiment
From which of the following studies can one most reasonably determine cause and effect?
null; alternative
H0 is to Ha as _____ hypothesis is to _____ hypothesis.
.70
If 49% of the total variability of Y is accounted for by X, what is the value of r?
all the points must fall on a straight or curved line
If a correlation is perfect,
negatively skewed
If a distribution of raw scores is negatively skewed, transforming the raw scores into z scores will result in a _________ distribution.
the relation can be most accurately represented by a straight line
If a relationship is linear, _________.
we would expect the results to occur by chance less than 5 times out of 100.
If researchers report that the results from their study were significant, p < .05, this means that
mean
If the distribution is symmetrical, which is the best measure of central tendency?
as X increases, Y decreases
In a negative relationship, _________.
70%
In a normal distribution approximately _________ of the scores will fall within 1 standard deviation of the mean.
0, the z score for the mean, and the z score for the mode
In a normal distribution the z score for the mean equals _________.
MSBetween; MSError
In a repeated-measures ANOVA, the final F ratio is determined by dividing _____ by _____.
between-groups, error, and participant variance
In a repeated-measures ANOVA, the total variance is comprised of
individual differences
In a repeated-measures design, the single largest contributing factor to error variance has been removed. What is that factor?
MSFactor A; MSError
In a two-way factorial ANOVA, the final F ratio for Factor A is determined by dividing _____ by _____.
MSA×B; MSError
In a two-way factorial ANOVA, the final F ratio for Factor A×B is determined by dividing _____ by _____.
MSFactor B; MSError
In a two-way factorial ANOVA, the final F ratio for Factor B is determined by dividing _____ by _____.
[Σ(XbarC -Xbar G)2nC] - SSA - SSB
In a two-way factorial ANOVA, the formula for calculating SSA×B is:
Σ[(XbarA -XbarG)2nA]
In a two-way factorial ANOVA, the formula for calculating SSFactor A is:
Σ(X-XbarG)^2
In a two-way factorial ANOVA, the formula for calculating SSTotal is:
A - 1
In a two-way factorial ANOVA, the formula for calculating dfFactor A is
SSA×B; dfA×B
In a two-way factorial ANOVA, to calculate MSA×B we divide _____ by _____.
SSError; dfError
In a two-way factorial ANOVA, to calculate MSError we divide _____ by _____.
SSFactor A; dfFactor A
In a two-way factorial ANOVA, to calculate MSFactor A we divide _____ by _____.
Type I error; Type II error
In decision making, when we make a false alarm it is similar to a _____ and when we make a miss it is similar to a _____.
sample
In order to estimate the attention level of college undergraduates in the United States, a psychologist measures the attention span of the undergraduates at a local university. The undergraduates at the local university are a _________.
population
In order to estimate the average (mean) weight of all professional football players, an investigator determines the weight of the "Dallas Cowboy" players. All professional football players constitute a _________.
variables
In the equation Y = bX + a, X and Y are _________.
a constant giving the value of the Y axis intercept
In the equation Y = bX + a, X and Y, a is _________.
a constant and the slope of a line
In the equation Y = bX + a, X and Y, b is _________.
good memory causes high IQ
Knowing nothing more than that IQ and memory scores are correlated 0.84, you could validly conclude that _________.
a statistic
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. The average (mean) number of seizures for the 20 subjects is called _________.
independent variable
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. The new drug is ----------
0 and 1
Probabilities vary between _________.
ratio
Reaction time in seconds is an example of a _________ scale.
the table can be used with both positive and negative z values because it is symmetrical
Table A in your textbook has no negative z values, this means _________.
0.50
The proportion of scores less than z = 0.00 is _________. (assume normal distribution)
r2
The proportion of variance accounted for by a correlation between two variables is determined by
1
The standard deviation of the z distribution equals _________.
it has no negative values, it is positively skewed and there are a family of F curves uniquely determined by df(numerator) and df(denominator)
True or False- Which of the following is (are) true about the F distribution?
true
True or False- z scores allow comparison of variables that are measured on different scales.
lower the correlation
When a correlation exists, lowering the range of either of the variables will _________.
one-tailed
When using a _____ hypothesis the researcher predicts the direction of the expected difference between the groups.
increasing N and increasing the effect of the independent variable
Which of the following increase(s) the power of the t test?
the groups are independent
Which of the following is not an assumption of the one-way repeated measure ANOVA?
The relationship between the two variables must be nonlinear.
Which of the following statements concerning Pearson r is not true?
self-rating of anxiety level by students in a statistics class - ratio
Which of the following variables has been labeled with an incorrect measuring scale?
Parametric tests; nonparametric tests
_____ are most often used with interval or ratio data whereas _____ are most often used with ordinal or nominal data.
inferential
_____ statistics are used in the process of hypothesis testing.