Question 1

On a normal curve,99 percent of all the cases would be found between which two standard deviations (SDs)?

Accepted Answer

In a normal distribution, approximately 99.7% of data falls within three standard deviations from the mean, so 99% would be very close to this range, between -3 and +3 SDs.

Question 2

When two variables vary together in some orderly fashion,they are

Accepted Answer

When two variables vary together in some orderly fashion, they are said to be correlated. This means that as one variable changes, the other variable also changes in a predictable way. However, it does not necessarily mean that one variable causes the other variable to change.

Question 3

What percent of all cases are found between an SD of +1 and an SD of -1 on a normal curve?

Accepted Answer

The empirical rule states that approximately 68% of all cases fall within one standard deviation of the mean on a normal curve. Therefore, choice B is the correct answer.

Question 4

On a normal curve,95 percent of all the cases would be found between which two standard deviations (SDs)?

Accepted Answer

According to the empirical rule, approximately 95% of the data falls within two standard deviations of the mean. Therefore, the answer would be -2 and +2 standard deviations from the mean, which is option C.

Question 5

Groups of scores from distributions that are approximately normal can be compared because the relationship does not change between the normal curve and the

Accepted Answer

The answer of Groups of scores from distributions that are...

Question 6

Dr.Lancer noted in his observations that people who are susceptible to hypnosis are also more likely to listen to music.Dr.Lancer is describing a relationship called a

Accepted Answer

Dr. Lancer is describing a relationship between two variables, in this case, susceptibility to hypnosis and likelihood to listen to music. This is an example of a correlation.

Question 7

A psychologist notes that the higher a couple's socioeconomic and educational status,the smaller the number of children they are likely to have.This psychologist is describing a relationship called a

Accepted Answer

The psychologist is describing a correlation between socioeconomic/educational status and the number of children a couple is likely to have. Correlation refers to the relationship or association between two variables, indicating a pattern or tendency for them to fluctuate together. Therefore, option C - correlation - is the most fitting choice. Statistical significance, standard deviation, and normal curve are concepts related to statistical analysis and inferential statistics, which are not explicitly relevant to the given scenario.

Question 8

On a normal curve,68 percent of all the cases would be found between which two standard deviations (SDs)?

Accepted Answer

The empirical rule states that 68 percent of all cases fall within one standard deviation of the mean. The options (-1 and +1) represent one standard deviation on either side of the mean, so this is the correct choice. Options A (-2 and +2) and D (-3 and +3) represent two and three standard deviations away from the mean, respectively, which would include more cases and not fit the 68 percent rule. Option C (-2 and +2) would be correct if the question asked for the range that covers 95 percent of all cases (i.e., within two standard deviations of the mean).

Question 9

A graph that plots the intersection of paired measures,that is,the points at which paired X and Y measures cross is called a

Accepted Answer

A scatter diagram is a graph that plots the intersection of paired measures, which are essentially X and Y values that are paired together. It is a useful tool for identifying potential relationships and patterns between variables. Histograms, frequency polygons, and frequency distributions are all graphs that represent the distribution of a single variable, and do not involve the intersection of paired measures.

Question 10

For a group of students,a researcher obtains their grades in high school and their grades in college and plot the intersection of these paired measures for each person on a graph as a single point.This graph is called a

Accepted Answer

The graph described is a scatter diagram, which plots paired measures for each person as a single point. The other options (normal curve, correlation matrix, frequency distribution) do not accurately describe this type of graph.

Question 11

A correlation describes the

Accepted Answer

A correlation describes the relationship between two variables. It measures the degree to which they are linearly related. It does not indicate the probability of a variable occurring or the mean and median of a variable. While commonality may be a factor in correlation, it is not the primary focus.

Question 12

When measure X gets smaller,measure Y also gets smaller in a

Accepted Answer

The answer of When measure X gets smaller,measure Y also...

Question 13

Which of the following is NOT an example of a question that could be answered using a correlational study?

Accepted Answer

Correlational studies examine the relationship between two variables, but do not establish causation. Option A asks about the cause and effect relationship between a drug and memory, which cannot be answered with a correlational study.

Question 14

The existence of a consistent,systematic relationship between two events,measures,or variables refers to

Accepted Answer

A consistent, systematic relationship between two events, measures, or variables is referred to as a correlation. Statistical significance refers to the likelihood that a correlation is not due to chance. A standard deviation is a measure of variability. A normal curve is a specific type of probability distribution.

Question 15

Josh is viewing a scatter diagram and notes that as measure X gets larger,measure Y gets smaller.Thus,this scatter diagram is depicting a

Accepted Answer

In a scatter diagram, if as one variable (X) increases, the other variable (Y) decreases, it is indicative of a negative relationship or negative correlation. Therefore, the best choice is D.

Question 16

Which of the following is NOT an example of a correlational study?

Accepted Answer

A is not an example of a correlational study because it is testing whether a specific intervention (new reading curriculum) will have an effect on the outcome measure (reading comprehension test scores), rather than just measuring the relationship between two variables. The other options are all examples of correlational studies because they are investigating the relationship or association between two variables without manipulating any independent variable.

Question 17

In order to clearly visualize the correlation,Dr.Amott should construct a

Accepted Answer

A scatter diagram is the best choice for visualizing the correlation between two variables as it displays the relationship between them through the placement of points on a graph. Other options such as a histogram, frequency polygon, and frequency distribution are better suited for displaying the distribution of a single variable.

Question 18

When measure X gets larger,measure Y also gets larger in a

Accepted Answer

In a positive relationship, as one variable increases, so does the other variable. Therefore, as measure X gets larger and measure Y also gets larger, it suggests a positive relationship between the two measures.

Question 19

What percent of all cases are found between a standard deviation (SD)of +2 and an SD of -2 on a normal curve?

Accepted Answer

The answer of What percent of all cases are found...

Question 20

On his psychology test,Miguel must determine what percent of all cases are found between a standard deviation (SD)of +3 and a standard deviation (SD)of -3 on a normal curve.His answer to this problem should be __________ percent.

Accepted Answer

The answer of On his psychology test,Miguel must determine what...

Quiz 79: Behavioral Statistics

On a normal curve,99 percent of all the cases would be found between which two standard deviations (SDs) ?