Psychology Stats Final M.C.

In stating H0 and H1, one must be certain that they are ___. a. mutually exclusive b. independent c. exhaustive d. a series of N trials e. a and c

e

The sampling distribution of the mean gives ____. a. all the values the sample mean can take b. the probability of getting each mean value if sampling is random from the H0 population. c. all the values the standard deviation can take d. the probability of getting each standard deviation value if sampling is random from the H0 population e. a and b

e

Which of the following statement(s) is (are) an important consideration(s) in applying linear regression techniques? a. The relationships should be linear b. Both variables must be measured in the same units c. Predictions for Y should be within the range of the X variable in the sample d. All of the above e. A and C

e

Which of the following would cause Fobt to increase a. an increase in the difference between means b. an increase in the within-groups variability c. an increase in the magnitude of the independent variable's effect d. a and b e. a and c

e

A discrete scale of measurement ____. a. provides exact measurements b. never provides exact measurements c. can take an infinite number of intermediate possible values d. b and c

a

A normally distributed set of population scores has a mean of 65 and a standard deviation of 10.2. The standard error of the mean, for samples of size 48 equals ____. a. 1.47 b. 10.2 c. 65 d. none of the above

a

∑(Y-Y')² represents a. variance b. standard error of estimate c. total error of prediction d. standard deviation

c

In an independent groups experiment, if we must estimate the population standard deviation to determine the significance of the sample results, the appropriate inference test is the ____. a. t test b. sign test c. z test d. none of the above

a

In the t test for independent groups, the unbiased estimate of the population variance is ____. a. a weighted average of s1^2 and s2^2 b. s^2 alone c. s1^2 alone d. none of the above

a

If you reject the null hypothesis, you may be making ____. a. a Type II error b. a Type I error c. a correct decision d. a and c e. b and c

a

Nominal or ordinal data may be plotted as a ____. a. bar graph b. histogram c. frequency polygon d. b and c

a

Sample data: 5, 5, 6, 7, 8. What is the mean? (show formula) a. 6.2 b. 5.2 c. 7.2 d. 8.2

a

Sample data: 5, 5, 6, 7, 8. What is the median? a. 6 b. 5 c. 7 d. 8

a

As sample size increases, ϴx ____. a. decreases b. increases c. stays the same d. approaches ϴ

a

Sample data: 5, 5, 6, 7, 8. What is the mode? a. 6 b. 5 c. 7 d. 8

b

A priori probability refers to ____. a. a probability value deduced from reason alone b. low priority probability c. a probability value determined after collecting data d. none of the above

a

An alpha level of 0.05 indicates that ____. a. if H0 is true, the probability of falsely rejecting it is limited to 0.05 b. 95% of the time, chance is operating c. the probability of a Type II error is 0.05 d. the probability of a correct decision is 0.05

a

Consider the following scores: 97, 98, 80, 85, 75, 70, 72, 78. Which of the measures listed would give the best description of the central tendency of these scores. a. mean b. variance c. median d. mode

a

The assumption of homoscedasticity is that: a. the variability of Y doesn't change over the X scores b. the variability of X and Y distributions is the same c. The range of Y scores is the same as X scores d. The X and Y distributions have the same mean value

a

Two events are independent if ____. a. The occurrence of one has no effect on the probability of occurrence of the other b. The occurrence of one precludes the occurrence of the other c. The occurrence of one substantially alters the probability of the other d. The sum of their probabilities equals one

a

When the relation between X and Y is perfect, the prediction of Y given X is ____. a. perfect b. always equal to Y c. impossible to determine d. approximate

a

Which of the following variables has been labeled with an incorrect measuring scale? a. reaction time in an experiment - interval b. ranking in a beauty contest - ordinal c. sex of children - nominal d. Fahrenheit scale of temperature - interval

a

If a distribution of raw scores is positively skewed, transforming the raw scores into z scores will result in a ____ distribution. a. Bell-shaped b. Positively-skewed c. Normal d. Negatively-skewed

b

If bY is positive, higher scores of X are associated with ____. a. Lower scores of X' b. Higher values of Y c. Higher values of (Y-Y') d. Lower values of Y

b

If one or both variables are ordinal scaled and the relationship is linear, what type of correlation coefficient is most approximate? a. Pearson r b. Spearman rho c. Eta d. Phi

b

If the alternative hypothesis states that studying affects grade point average, the null hypothesis states ____. a. studying does not increase grade point average b. studying has no effect on grade point average c. studying increases grade point average d. P does not equal Q

b

If the correlation between two sets of scores is 0 and one had to predict the value of Y for any given value of X, the best prediction of Y would be ____. a. bY b. ȳ c. 0 d. x̄

b

In order to estimate the average (mean) of the flexibility of all college athletes in the United States, an investigator determines the flexibility of college athletes at UND. The average (mean) flexibility of all college students in the United States is called a ____. a. population b. paramater c. sample d. statistic

b

In the equation, Y= bX + A, what is the value of b? a. the Y axis intercept b. the slope of th eline c. a and b d. a variable

b

Let's assume that we have determined the salary of all professors at your school. In plotting the distribution of salaries we notice that it is negatively skewed. For this distribution ____. a. mean = median b. mean < median c. mean > median d. can't tell from the information given

b

Student's t test for correlated groups really reduces to ____. a. the sign test b. Student's t test for single samples using different sources c. Students t test for independent groups d. none of the above

b

The advantage of a powerful experiment is that ____. a. the probability of a Type I error is reduced b. you are more likely to detect the real effects of the independent variable, if there are any c. as power increases, alpha increases d. as power increases, N increases

b

The mean of the z distribution equals ____. a. 1 b. 0 c. the mean of the raw scores d. N

b

When analyzing data from experiments that involve more than two groups ____. a. doing t tests on all possible pairs of means increases the probability of making Type II errors b. doing t tests on all possible pairs of means increases the probability of making Type I errors c. it is generally permissible to do t tests between all possible pairs of means and use Student's t distribution d. doing t tests on all possible pairs of means decreases the probability of making Type I errors

b

Which of the following represents the strongest relationship between X and Y? a. r= 0.49 b. r= -0.86 c. r= 0.68 d. r= -0.56

b

A historical study has shown that the correlation between juvenile delinquency and self-esteem is -0.95. This study implies that: a. low self esteem causes juvenile delinquency b. juvenile delinquency causes low self-esteem c. causation cannot be implied d. none of the above

c

A normally distributed set of population scores has a mean of 65 and standard deviation of 10.2. The mean, of the sampling distribution of the mean, for sample size 48 equals ____. a. 1.47 b. 10.2 c. 65 d. none of the above

c

A posteriori probability refers to ____. a. a probability value deduced from reason alone b. low priority probability c. a probability value determined after collecting data d. none of the above

c

Consider the following scores: 97, 98, 80, 85, 75, 70, 2, 0, 4. Which of the measures listed would give the best description of the central tendency of these scores. a. mean b. variance c. median d. mode

c

Correlation and regression differ in that ____. a. correlation is primarily concerned with the size and direction of relationships b. regression is primarily used for prediction c. both a and b d. none of the above

c

In order to estimate the average (mean) of the flexibility of all college athletes in the United States, an investigator determines the flexibility of college athletes at UND. The college students at UND are called ____. a. population b. parameter c. sample d. statistic

c

Let's assume that we have determined the salary of all professors at your school. In plotting the distribution of salaries we notice that it is positively skewed. For this distribution ____. a. mean = median b. mean < median c. mean > median d. can't tell from the information given

c

SB^2(MSbetween) is a measure of ____. a. ϴ^2 alone b. ϴ^2 alone + the effects of the independent variable c. the variability between the means d. b and c

c

The alpha level ____. a. is always set at 0.05 or 0.01 b. is set after the data are analyzed c. is determined by the consequences of making a Type 1 and Type II error. d. depends on N

c

When N is less than infinity, | tcrit | for any alpha level is ____ | zcrit |. a. the same as b. less than c. greater than d. dependent on N

c

A priori comparisons ____. a. are planned in advance of the experiment b. often arise out of theory and prior research c. may be done without obtaining a significant F in the one-way ANOVA d. all of the above

d

If a distribution of raw scores is negatively skewed, transforming the raw scores into z scores will result in a ____ distribution. a. Bell-shaped b. Positively-skewed c. Normal d. Negatively-skewed

d

If alpha is changed from 0.05 to 0.01, ____. a. the probability of a Type II error decreases b. the probability of a Type I error increases c. the error probabilities stay the same d. the probability we will retain a false H0 increases

d

If bY is negative, higher scores of X are associated with ____. a. Lower scores of X' b. Higher values of Y c. Higher values of (Y-Y') d. Lower values of Y

d

If you retain the null hypothesis, you may be making ____. a. a Type II error b. a Type I error c. a correct decision d. a and c e. b and c

d

In order to estimate the average (mean) of the flexibility of all college athletes in the United States, an investigator determines the flexibility of college athletes at UND. The average (mean) flexibility of college students attending UND is called ____. a. population b. parameter c. sample d. statistic

d

Interval data may be plotted as a ____. a. bar graph b. histogram c. frequency polygon d. b and c

d

One employs a correlated groups design ____. a. to eliminate random error b. to specify calculations c. for prediction d. to reduce the effects of individual differences among subjects

d

When the relation between X and Y is imperfect, the prediction of Y given X is ____. a. perfect b. always equal to Y c. impossible to determine d. approximate

d

Which of the following is NOT a property of the mean? a. The mean is sensitive to the exact value of all the scores. b. The sum of the deviations about the mean equals zero. c. The sum of the squared deviations about the mean is a minimum. d. The mean is most subject to sampling variation e. The mean is most affected by extreme scores

d

If a test is a robust test, ____. a. it is sensitive to its underlying mathematical assumptions b. it doesn't estimate any population parameters c. it is insensitive to its underlying mathematical assumptions d. it often may be used despite violations of its underlying mathematical assumptions e. c and d

e

If alpha is changed from 0.01 to 0.05, ____. a. the probability we will retain a false H0 increases b. the probability of a Type II error decreases c. the probability of a Type I error increases d. the error probabilities stay the same e. b and c

e