Stats Waiver Exam

If Rsquared = .25, what percentage of the variance is accounted for? A 25% B 75%

A 25%

In a normal distribution with a mean of 90.00 and a standard deviation of 10.00, what percentage of the cases lies between scores of 80 and 90? A 34% B 50% C 68%

A 34%

Random sampling identifies a sample that: A Contains sampling errors B Is free of all errors C is Biased

A Contains sampling errors

In a scattergram for a weak relationship, there is: A much scatter B little scatter

A Much scatter

If an employer ranks employees from low to high on customer service, the employer is using what scale of measurement? A Ordinal B Interval C Ratio D Nominal

A Ordinal

When a curve has a tail to the right but no tail to the left, it is said to have a: A Positive skew B Negative skew

A Positive skew

For determining the correlation between a combination of two predictors to predict a third variable, which of the following should be computed? A R B r

A R

Suppose a researcher was examining the validity of a combination of hours spend doing homework and attitudes toward school as predictors of grades in a course. Which correlational statistic should the researcher compute for this research problem? A R B r

A R

To determine the opinions of all bicycle owners in a city, a researcher surveys the customers at two bicycle shops that happen to be near her residence. she is using a: A sample of convenience B simple random sample

A Sample of convenience

If you read that t = 2.234, df =60, p>. .05, what should you conclude? A the difference is statistically significant B the difference is not statistically significant

B

The smaller the variability in a population, the A larger the standard error of the mean B smaller the standard error of the mean

B

Under which of the following circumstances is the null hypothesis more likely to be rejected? A when there is much variation in the population B when there is little variation in the population

B

What is the first step in computing Cohen's d? A Subtract the experimental group's mean from the control group's mean B Subtract the control group's mean from the experimental group's mean C Divide the experimental group's mean by the control group's standard deviation

B

Which group has a smaller standard deviation? A Scores for group 1: 10, 20, 30, 40, 50 B Scores for group 2: 30, 31, 32, 33, 34

B

Which of the following is correct statement of the null hypothesis? A The observed difference between the means was created by bias. B The observed difference between the means was created by sampling error

B

If 25 out of 100 parents favor an extended school day, what percentage favors it? A 2.5 B 25 C 50 D Some other percentage

B 25

Suppose a researcher randomly selected 30 classrooms (as clusters). Each classroom had 10 students. The researcher should report the sample size as A 10 B 30 C 300

B 30

If there are 2,000 adult citizens in a town and 20% favor building a new public library, how many favor it? A 200 B 400 C Some other number

B 400

Which type of study is recommended in order to study causation? A A correlational study B An experimental study

B An experimental study

Which of the following is a symbol for an alternative hypothesis? A H0 B H1

B H1

Which average is defined as the middle point in a distribution? A Mean B Median C Mode

B Median

The mean is not associated with which one of the following scales of measurement? A Interval B Nominal C Ratio

B Nominal

Which of the following values of R represents the strongest relationship? A R = .00 B R=-1.00 C R=.95

B R=-1.00

Suppose participants were classified according to their major in school and their gender in order to compare means for both major and gender. This would call for a A. One-way ANOVA B two way ANOVA

B Two way ANOVA

A percentage is an example of: A an inferential statistic B a descriptive statistic

B a descriptive statistic

An average is an example of: A an inferential statistic B a descriptive statistic

B a descriptive statistic

For the scores on Test F and Test G shown below, there is: A a direct relationship B an inverse relationship C no relationship

B an inverse relationship

Which type of planning involves constructing or selecting measuring instruments? A whom B how C when D under what circumstances

B how

Suppose you read that as a result of a chi-square test, p> .05. By conventional standards what decision should be made about statistical significance? A it is significant B it is not significant

B it is not significant

Suppose you read the following, F=2.20, df=4, p>.05. What conclusion would you normally draw about statistical significance? A it is statistically significant B it is not statistically significant

B it is not statistically significant

In the social and behavioral sciences, it is common to find scattergrams with A no scatter B some scatter

B some scatter

For a given value of the Pearson r, the coefficient of determination is computed by: A taking the square root of r B squaring the r

B squaring the r

Which of the following is usually superior? A simple random sampling B stratified random sampling

B stratified random sampling

A correlation coefficient is based on one group's performance on how many variables? A one B two or more

B two or more

Failing to reject the null hypothesis when in reality it is false is known as a: A type 1 error B type 2 error

B type 2 error

If you compute the deviations from the mean for a set of scores and then sum the deviations, what sum will you get? A 100 B 10 C 0 D Some other number

C 0

What is the mode of the following scores. Scores : 1, 1, 1, 4, 5, 6 A 4 B 3 C 1 D Some other value

C 1

When the coefficient of determination equals .70, what percentage of the variance on one variable is not predicted by the other variable? A 70% B 49% C 30% D Some other percentage

C 30%

In a normal distribution, what percentage of the cases lies between one standard deviation unit above the mean and one standard deviation unit below the mean? A 34% B 50% C 68%

C 68%

What scale of measurement has an absolute zero? A Ordinal B Interval C Ratio D Nominal

C Ratio

If all participants in a group have the same score, the standard deviation of their scores equals: A 1 B 100 C Some other value

C Some other value

Putting 100 names in a hat, mixing them thoroughly and drawing out 10 names consitutes: A cluster sampling B stratified random sampling C simple random sampling

C simple random sampling

For the typical consumer of research, which of the following values in an ANOVA table is of greatest interest? A Mean squares B Sum of squares C the value of p

C the value of p

The observations that researchers make result in what?

Data

True or False: For the data in the following table, a one-way chi-square would be an appropriate test of significance YES. NO Men. n=30. n=40 Woman n=40. n=30

False

True or False: If a t test yields p> .05, the null hypothesis normally would be rejected.

False

True or False: In the table below, there appears to be an interaction x. y D. m=10. m=20 E m=20. m=30

False

True or False: Independent data may have less sampling error than dependent data.

False

True or False: It is appropriate to convert a Pearson r to a percentage by multiplying it by 100.

False

True or False: Knowing the value of p tells us the size of the difference.

False

True or False: Proportions are usually easier to interpret than percentages"

False

True or False: Statistical significance is synonymous with practical significance.

False

True or False: The .01 level is a higher level of significance than the .001 level

False

True or False: The acronym ANOVA stands for Alternative Number of Variance Approach.

False

True or False: The null hypothesis is a statement about the size of the difference.

False

True or False: The purpose of the effect size is to determine the statistical significance of the difference between two means.

False

True or False: Using a large sample eliminates bias

False

True or False: Using a very large sample is the most important characteristic of a good sample

False

True or False: each dot in a scattergram stands for a participants score on one variable"

False

Yes or No: Are scattergrams frequently presented in research reports?

No

Yes or No: Does the use of stratified random sampling eliminate all sampling errors?

No

Yes or no: Are the data that researchers collect always "scores"?

No

Yes or no: Is a small difference necessarily an insignificant difference?

No

In which type of study are no treatments given?

Nonexperimental

Suppose a researcher gave welfare recipients 2 types of job training to see which type was more effective in helping them get jobs. Getting jobs is the ______ variable

dependent

True or False: The ratio scale of measurement is a higher level of measurement than the interval scale.

True

True or False: The standard deviation is based on the differences between the scores in a distribution and their mean

True

True or False: The uppercase letter X with a bar over it is a symbol for the mean

True

True or False: Using random sampling identifies an unbiased sample.

True

True or False: When a researcher rejects the null hypothesis the difference is declared statistically significant.

True

True or False: When reporting the results of a t test, the values of the means and standard deviations should first be reported

True

True or False: When the median is reported as the average for a set of scores, it is customary to report the interquartile range as a measure of variability.

True

The term empiricism refers to

the use of observation to obtain information

The symbol for chi-square is A 1 B ? C /

A 1

Which of the following values of r represents the strongest relationship? A. -1.00 B. 0.00 C. -.50

A -1.00

In order to examine a main effect, you A temporarily ignore one way that the participants were classified while examining the results of the other way they were classified B look at both ways participants were classified at the same time in order to see how the two classification variables affect each other.

A

What does it mean when d=0.50? A The average participant in the experimental group is one-half of a standard deviation higher than the average participant in the control group B The average participant in the control group is one-half of a standard deviation higher than the average participant in the experimental group

A

Which of the following will produce a greater reduction in sampling errors? A Increasing the size of a sample from 100 to 150 (an increase of 50) B increasing the size of a sample from 300 to 350 (an increase of 50)

A

For the scores on Test D and Test E shown below, there is: A a direct relationship B an inverse relationship C no relationship

A a direct relationship

Decreasing sample size A decreases precision B decreases bias C decreases precision and decreases bias

A decreases precision

When high scores on one variable are associated with high scores on the other variable, this suggests that the relationship is A direct B inverse

A direct

If participants are randomly assigned to experimental and control groups without matching (ie pairing) the resulting data are A independent B dependent

A independent

By conventional standards, if p>.05, a researcher would declare the difference statistically A insignificant B significant

A insignificant

If you decrease the sample size, what effect does this have on the size of the standard error of the mean? A it increases it B it decreases it

A it increases it

Suppose you read that as a result of a chi-square test, p<.01. By conventional standards, what decision should be made about the null hypothesis? A reject it B Do not reject it

A reject it

Suppose you read the following: F=4.641, df =3, p<.0J. What conclusion would you normally draw about the null hypothesis? A Reject it B Do not reject it

A reject it

Suppose that you read p<.05 for an interaction. By conventional standards, you should declare the interaction. A statistically significant B not statistically significant

A statistically significant

Which of the following is an example of a nonexperimental study? A survey of political attitudes A study with a control group A sutdy with treatments

A study with a control group

At what point is it conventional to not reject the null hypothesis? A when p >.05 B when p < .05

A when p > .05

True or False: The range is a statistic that describes variability.

True

If a researcher concludes that a difference is statistically significant, what else is true? A the null hypothesis should not be rejected B the null hypothesis should be rejected

B

True or False: The larger the sample, the more likely the null hypothesis will be rejected.

True

True or False: The lowest level of measurement is the nominal level.

True

If m=90 and SEM =4.00, what are the limits of the 68% confidence interval for the mean? A 86.00 and 90.00 B 90.00 and 94.00 C 4.00 and 8.00 D 86.00 and 94.00

D

Suppose there are 1,100 people in a population and you want to draw a sample using a table of random numbers. Which of the following would be an appropriate number name for the first person to whom you assign a number before using the table? A 01 B 100 C 001 D 0001

D 0001

In the following set of scores, which score is an outlier? Scores: 1, 1, 3, 4, 6, 7, 30 A 1 B 4 C 7 D 30

D 30

If students name their favorite sport, the resulting data are at what level? A Ordinal B Interval C Ratio D Nominal

D Nominal

If the median for a set of scores equals 136, what percentage of the scores is below 136? A 25% B 33% C 75% D Some other percentage

D Some other percentage

When there is a perfect, direct relationship, what is the value of r? A. 0.50 B 0.00 C. -1.00 D Some other value

D Some other value

When researchers systematically use the empirical approach to acquire knowledge, we say they are engaging in what?

Empirical research

Even the best plans for research often cannot be fully executed for physical reasons. What are some reasons?

Ethical, legal and financial constraints

True or False "It is impossible for a relationship to be both inverse and strong"

False

True or False - Organizing and summarizing data is only a minor function of statistics

False

True or False - The participants' responses in an experiment constitute the independent variable

False

True or False - When researchers rely on authority for knowledge they are using the empirical approach to knowledge

False

True or False: "For large populations with very limited variability, very large samples are needed for sufficient precision"

False

True or False: "In a distribution with a positive skew, the median has a higher value than the mean"

False

True or False: "Income in large populations usually forms a normal curve when plotted"

False

True or False: "The interquartile range is defined as the range of the middle 25% of the participants"

False

True or False: "The null hypothesis states that the difference between the means in the population is greater than zero"

False

True or False: "The symbol for the coefficient of determination is r"

False

True or False: "When r=20, the percentage of variance accounted for is 20%"

False

True or False: An inverse relationship is sometimes called a positive relationship.

False

True or False: An r of -.45 represents a stronger relationship than an r of .88

False

True or False: For most practical purposes, values of d often exceed 10.0

False

True or False: For nominal data, a researcher normally reports means and standard deviations.

False

Which of the following is obtained when we study samples? Parameters Statistics

Statistics

What is the name for a subset of a population?

Sample

True or False: The mean can be misleading when used to describe skewed distributions

True

True or False - Both everyday observation and research can be misleading

True

True or False - the purpose of an experiment is to identify cause and effect relationships

True

True or False" Inferential statistics are tools that indicate how much confidence researchers can have when they generalize from a sample to a population"

True

True or False: "A normal curve is also called a bell-shaped curve"

True

True or False: "Even small samples can identify very large differences"

True

True or False: "For a given study, the research hypothesis usually is inconsistent with the null hypothesis"

True

True or False: "For a percentage of 79%, the corresponding proportion is .79

True

True or False: "For an r of .60, the ability to predict is 36% better an zero"

True

True or False: "In descriptive statistics, the letter N stands for number of participants in a population.

True

True or False: "The mean is a measure of centra/tendency"

True

True or False: "The median is insensitive to extreme scores"

True

True or False: "When a distribution is skewed to the right it is said to have a positive skew"

True

True or False: "When the dots in a scattergram form a pattern from the lower left to the upper right, the relationship is direct"

True

True or False: "Whichever hypothesis a researcher believes is true at the beginning of a study is the research hypothesis"

True

True or False: A frequency distribution is a table that shows how many participants have each score.

True

True or False: A population may be large or small

True

True or False: A small effect size might represent an important result.

True

True or False: A synonym for the term variability is spread

True

True or False: A t test yields a probability that the null hypothesis is correct.

True

True or False: ANOVA can be used to test for the differences among two or more means.

True

True or False: According to the central limit theorem, the sampling distribution of means is normal

True

True or False: In a direct relationship, those who are high on one variable tend to be high on the other variable.

True

True or False: In the table below there appears to be an interaction: S. T U M=100. M=200 V. M=200. M=100

True

True or False: Random sampling identifies a sample that is subject to sampling errors.

True

Yes or No: Does everyday observation employ the empirical approach?

Yes

Yes or no: Is it possible for a large, significant difference to have little practical significance?

Yes

Yes or no: Is the variability among scores one of the factors that contribute to determining statistical significance?

Yes

Research differs from everyday observation primary because researchers

plan their observations in advance

If there are 200 nurses employed by a hospital and 50 are selected for observation, the 200 are known as a

population