PSYCH 3020 Final
in a normal distribution the z score for the mean equals ______
0, the z score for the median, and the z score for the mode
the t distribution is the same for all sample sizes
false
the t test for single samples is used when the population parameter is μ is unknown
false
when a sampled score is put back in the population before selecting the next score, this process is called sampling without replacement
false
when calculating the population standard deviation, we use N-1 in the denominator
false
which of the following are true
fo is the symbol for the observed frequency, fe is the symbol for the expected frequency, and c2 is the symbol for chi-squared
Fobt=(SSbetween/dfbetween)/(SSwithin/dfwithin)
true
SStotal=SSwithin + SS between
true
a percentile rank is a score that indicates the percentage of people who scored at or below a given raw score
true
a value of -1.0 for Fobt is never possible if the calculations are done correctly
true
an assumption of c2 is that the scores in each cell are independent
true
as N increases, σx̅ decreases
true
c2 is basically a measure of the overall discrepancy between fe and fo
true
c2obt cannot be negative
true
if F < 1 the independent variable has not had a significant effect
true
if F < 1.0 we don't even have to bother to look up Fcrit since the result cannot possibly be significant
true
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
true
in a 2 x 2 table there are (r-1)(c-1) degrees of freedom
true
in a positively skewed distribution the mean has a higher than the median
true
in general, nonparametric tests have fewer requirements or assumptions about population characteristics than parametric tests do
true
the F distribution has no negative values
true
the addition rule is concerned with determining with probability of A or B, while the multiplication rule is concerned with determining the probability A and B
true
the area beyond a z score of +2.58 is .005
true
the degrees of freedom equal N-1 for the t test for single samples
true
the normal curve never touches the x axis
true
the range is equal to the highest score minus the lower score
true
the symbol SS stands for sum of squares
true
the symbol for the mean of the sampling distribution of the means is μ sub x̅
true
the t distribution is a family of curves that vary with the degrees of freedom
true
the t test for correlated groups is just like the t test for single samples except that it analyzes difference scores
true
the variance is the square of the standard deviation
true
to use the z test μ and σ must be known
true
z scores allow comparison of variables that are measures on different scales
true
an observed difference between two descriptive statistics that is unlikely to have occurred by chance represents
statistical significance
given the following set of sample raw scores, X: 1, 3, 4, 6, 8. what is the z transformed value for the raw score of 3?
-0.52
which of the following z scores represent the most extreme value in a distribution of scores assuming they are normally distributed?
-3.12
Five students were tested before and after taking a class to improve their study habits. They were given articles to read which contained a known number of facts in each story. After the story each student listed as many facts as he/she could recall. The following data was recorded. Before 10 12 14 16 12 After 15 14 17 18 20 The obtained value of the appropriate statistic to evaluate H0 is _________.
3.51
if an experiment using frequency data tested the preference for 6 brands of soup, there would be _________ degrees of freedom
5
If SSwithin = 126, N = 28, k = 4, then what is the value of MSwithin?
5.25
if a population of scores is normally distributed, has a mean of 45 and a standard deviation of 6, the most extreme 5% of the scores lie beyond the score(s) of _________
56.76 and 33.24
given the following set of scores: X: 10, 12, 6, 8, 9, 11, 13, 13, 5, 0, 1 what is the median
9
the value of c2obt for the table below is ______ (assume equal probabilities for fe in each cell) 12 20 16 18 30
9.42
if a= 0.05 and df=4 the value of c2crit=_______
9.488
which of the following are examples of nonparametric tests
Mann-Whitney U test and Chi-square test
which of the following are nonparametric tests
Wilcoxon test, Mann-Whitney U test, Kruskal-Wallis test
"brand of soft drink" is measured on ______
a nominal scale
in order to estimate the attention level of college undergraduates in the US, a psychologist measures the attention span of the undergraduates at a local university. the undergraduates at the local university are _______
a sample
in mot situations parametric tests
are more powerful than nonparametric tests
if the distribution is symmetrical, which is the best measure of central tendency
mean
a liberal statistical test is one that
minimizes type II errors but increases type I errors
______ are most often used with interval or ration data whereas _______ are most often used with ordinal or nominal data
parametric tests; nonparametric tests
reaction time in second is an example of a ________ scale
ratio
Five students were tested before and after taking a class to improve their study habits. They were given articles to read which contained a known number of facts in each story. After the story each student listed as many facts as he/she could recall. The following data was recorded. Before 10 12 14 16 12 After 15 14 17 18 20 what do you conclude using a= 0.05 2 tail
reject H0; the class appeared to improve study habits
which of the following variables has been labeled with an incorrect measuring scale
self reading of anxiety level by students in a statistics class- ratio
which of the following are examples of parametric tests
t test and F test
a two way ANOVA has ____ and a three way ANOVA has
two independent variables; three independent variables
as sample size increases, σx̅
decreases
from which of the following studies can one most reasonably determine cause and effect
experimental study
Fobt = MSwithin/MSbetween
false
a significant Fobt value indicated that all the group means are significantly different from each other
false
if Fobt < Fcrit, we reject H0
false
if Fobt is significant, it is possible to tell which groups differ from which without further analysis
false
if c2 is negative then H0 must be false
false
if the raw score deviation is very positively skewed, the standard deviation of the z transformed scores will not equal 1.
false
in a single variable c2 experiment there are N-1 degrees of freedom
false
in a skewed distribution, the mean and median are equal
false
in general, the Kruskal-Wallis test is as powerful as parametric ANOVA
false
it is impossible to have a z score of 23.5
false
nonparametric tests are generally more powerful than parametric tests
false
parametric tests are always more desirable than nonparametric tests
false
probability values range from -1.00 to +1.00
false
the alternative hypothesis is an ANOVA can be either directional or nondirectional
false
the proportion of scores less than z=0.00 is ________ (assume normal distribution)
.50
for any distribution of scores ∑(X - µ) = _________
0
probabilities vary between _______
0 and 1
If SStotal = 20 and SSbetween = 14, SSwithin = _________.
6
if you have 15 red socks (individual, not pairs) 24 green socks, 17 blue socks, and 100 black socks, what is the probability you will reach in the drawer and randomly select a pair of green socks? (without replacement)
0.0228
the probability of throwing two ones with a pair of dice equals ______
0.0278
the mean attention span for adults in a certain village is 15 minutes with a standard deviation of 6.4. what is the probability of randomly selecting a sample of 30 scores from this population that has a mean attention span equal to or greater than 17 minutes
0.0436
if µ = 400 and σ = 100 the probability of selecting at random a score less than or equal to 370 equals
0.3821
a certain university maintains a colony of male mice for research purposes. the ages of the mice are normally distributed with a mean of 60 days and a standard deviation of 5.2 assume you randomly sample one mouse from the colony the probability his age will be between 55 and 70 days is _____
0.8041
the standard deviation of the z distribution equals _______
1
a factorial design has two levels of factor A and three levels of factor B with 6 subjects in each condition. the F ratio for factor A would have _____ degrees of freedom
1, 30
the mean attention span for adults in a certain village is 15 minutes with a standard deviation of 6.4. if the means of all possible samples of size 30 is taken from this population, σx̅ will equal ________
1.17
An economics test was given and the following sample scores were recorded: Individual A B C D E F G H I J Score 12 12 7 10 9 12 13 8 9 8 The z score for individual G is _________.
1.42
Five students were tested before and after taking a class to improve their study habits. They were given articles to read which contained a known number of facts in each story. After the story each student listed as many facts as he/she could recall. The following data was recorded. Before 10 12 14 16 12 After 15 14 17 18 20 assume there is a real effect. using Cohen's d, the size of effect for the improvement, equals _______
1.57
an industrial psychologist observed 8 drill press operators for one working day. she recorded the number of times each operator pressed the "faster" button instead of the "stop" button to determine whether the design of the control panel was contributing to the high rate of accidents in the plant. the resulting scores were as followed: X: 5, 2, 8, 2, 3, 2, 4, 12 the range of this distribution is _______
10
a standardized test has a mean of 88 and a standard deviation of 12. what is the score at the 90th percentile? assume a normal distribution
103.36
given the following set of scores: X: 10, 12, 6, 8, 9, 11, 13, 13, 5, 0, 1 what is the range
13
a factorial design has two levels of factor A and three levels of factor B with 6 subjects in each condition the F ration for the interaction of AxB would have _____ degrees of freedom
2, 30
An economics test was given and the following sample scores were recorded: Individual A B C D E F G H I J Score 12 12 7 10 9 12 13 8 9 8 The standard deviation of the distribution is _________.
2.11
in an experiment using the independent groups design, these are 10 subjects in one group and 12 subjects in the other group. degrees of freedom is equal to ____
20
given the following set of scores X: 10, 12, 6, 8, 9, 11, 13, 13, 5, 0, 1 what is the variance
20.6
given the following set of scores: X: 10, 12, 6, 8, 9, 11, 13, 13, 5, 0, 1 what is the value of (X-Xbar)^2
206
in a study with three levels of factor A, three levels of factor B, and 6 subjects in each condition, the dfs for factors A and B respectively would be ______ and _______
2;2
assuming the z scores are normally distributed, what is the percentile rank of a z score of -0.47
31.92
in a study with three levels of factor A, three levels of factor B, and 6 subjects in each condition, the dfs for the interaction of AxB would be
4
if the following scores were population scores x: 10, 12, 6, 8, 9, 11, 13, 13, 5, 0, 1 what would the standard deviation be?
4.33
if the population standard deviation is 19.0 and the sample size is 19, then the standard error equals _______
4.36
a normally distributed set of population scores has a mean of 65 and a standard deviation of 10.2. the mean of the sampling distribution of the means for samples of size 48 equals ______
65
in a normal distribution approximately _______ of the scores will fall within 1 standard deviation of the mean
68%
given the following set of scores X: 10, 12, 6, 8, 9, 11, 13, 13, 5, 0, 1 what is the mean
8
the dependent variable is the variable that is systematically manipulated
false
the median is most affected by unbalanced extreme scores
false
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 _____
a statistic
a continuous scale of measurement is different than a discrete scale in that a continuous scale ______
can take an infinite number of intermediate possible values
which of the following increase(s) the power of the t test
increasing N and increasing the effect of the independent variable
_____ statistics are used in the process of hypothesis testing
inferential
a distribution has a mean of 78 and a median of 92. the 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
classifying subjects on the basis of sex is an example of what kind of scale
nominal
H0 is it Ha as ______ hypothesis is to ______ hypothesis
null; alternative
concluding there is no effect of the independent variable is to the ______ hypothesis, as concluding these is an effect of the independent variable is to the ______ hypothesis
null; alternative
when using a ____ hypothesis the researcher predicts the direction of the expected difference between the groups
one-tailed
At the annual sailing regatta, prizes are awarded for 1st, 2nd, 3rd, 4th, and 5th places. these "places" comprise ______
ordinal scale
in order to estimate the average weight of all professional football players, an investigator determines the weight of the "Dallas Cowboys" all professional football players constitute a _________
population
An English teacher has been teaching a sixth grade composition class for many years. He has the feeling that over the past several years, the writing ability of students has changed. A national test of proficiency in composition was administered 5 years ago. The resulting distribution of scores was normally shaped, had a mean of 85 and a standard deviation of 10.9. In order to test his feeling, he gives his present class of 43 students the same proficiency test. The resulting mean is 80 and the standard deviation is 8.7. Using the z test with a = 0.052 tail, what is your conclusion?
reject H0; the present class appears deficient in composition writing
the sampling distribution of chi-squared is
skewed, varies with df, and is a theoretical distribution
table a in your textbook has no negative z values, this means ______
the table can be used with both positive and negative z values because it is symmetrical
20 students were given a 10 item quiz. five students scored 6, six students scored 7, and nine students scored 10. if we randomly select a student from these 20 students, the probability that his/her quiz score is at least 6 is 1
true
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 ________
type I error; type II error
failing to reject the null when we should have rejected it is a ______ error
type II
if researchers report that the results from their study were significant, p < .05 this means that
we would expect the results to occur by chance less than 5 times out of 100
An English teacher has been teaching a sixth grade composition class for many years. He has the feeling that over the past several years, the writing ability of students has changed. A national test of proficiency in composition was administered 5 years ago. The resulting distribution of scores was normally shaped, had a mean of 85 and a standard deviation of 10.9. In order to test his feeling, he gives his present class of 43 students the same proficiency test. The resulting mean is 80 and the standard deviation is 8.7. Using the z test with a = 0.052 tail, the appropriate critical value is _________.
zcrit= +/- 1.96
An English teacher has been teaching a sixth grade composition class for many years. He has the feeling that over the past several years, the writing ability of students has changed. A national test of proficiency in composition was administered 5 years ago. The resulting distribution of scores was normally shaped, had a mean of 85 and a standard deviation of 10.9. In order to test his feeling, he gives his present class of 43 students the same proficiency test. The resulting mean is 80 and the standard deviation is 8.7. The obtained value of the appropriate statistic for testing H0 is _________.
zobt= -3.01
in an independent groups design the nondirectional alternative hypothesis states _____
µ1 ≠ µ2
in a two way factorial ANOVA, the formula for calculating SStotal is:
Σ(X-Xbar sub G)^2
In a two way factorial ANOVA the formula for calculating SSfactorA is
Σ[(Xbar sub A -Xbar sub G)^2 n sub A]
