Question 1

Explain the phrase,"Correlation does not imply causation."

Accepted Answer

A correlation is not sufficient evidence to support a causal statement.The coefficient summarizes the degree to which scores on two variables "go together." That scores on two variables are correlated does not mean one variable causes the other.One possibility is that a third variable is causally related to both variables.

Question 2

The most commonly used measure of central tendency is the
A) mean.
B) median.
C) mode.
D) range.

Accepted Answer

The mean is the most commonly used measure of central tendency because it takes into account all the data values and provides a representative value for the entire dataset. It is calculated by adding up all the values and dividing by the total number of values. The other measures of central tendency, such as the median and mode, are useful in certain situations but are less commonly used than the mean. The range is not a measure of central tendency but rather a measure of variability in the data.

Question 3

Which of the following is not a measure of dispersion or variability?
A) range
B) variance
C) standard deviation
D) confidence interval

Accepted Answer

Confidence interval is a measure of the precision or uncertainty of an estimate, but it is not a measure of dispersion or variability. Range, variance, and standard deviation all measure the spread or variability of a distribution.

Question 4

A score that is extreme and does not "go with" other scores in the distribution is called an
A) error.
B) impossible value.
C) significant value.
D) outlier.

Accepted Answer

An outlier is a score that is significantly different from the other scores in the distribution. It may be due to measurement error or may represent a true extreme observation.

Question 5

Distributions of scores for two groups in an experiment can be compared by
A) arranging the "stems" for both groups in one stem-and-leaf display and the "leaves" for both groups in a second stem-and-leaf display.
B) preparing one stem-and-leaf display using the scores for both groups.
C) arranging a stem-and-leaf display for each group side-by-side.
D) none of these

Accepted Answer

Arranging a separate stem-and-leaf display for each group (option C) allows for easy comparison of the distributions of scores, as they are placed side by side. Option A is not ideal as it may be difficult to compare the two displays. Option B is not recommended, as it can lead to confusion and difficulty in interpreting the data. Option D is not a correct option as there must be some way to compare the groups.

Question 6

The standard deviation is equal to the square root of
A) the variance.
B) the sum of squared deviations from the mean.
C) N - 1.
D) the standard error of the mean.

Accepted Answer

The standard deviation is defined as the square root of the variance, which is the average of the squared deviations from the mean. Therefore, choice A is the correct answer. Choice B is the definition of the variance, not the standard deviation. Choice C is unrelated to the calculation of the standard deviation. Choice D refers to the standard error of the mean, which is a measure of the variability of sample means, not individual values, and is calculated differently from the standard deviation.

Question 7

A coherent "story" of data analysis for a study will include
A) an explanation of the findings.
B) counter arguments for opposing interpretations of the findings.
C) justifications for conclusions.
D) all of these

Accepted Answer

A coherent story of data analysis for a study should not only include an explanation of the findings, but also counter arguments for opposing interpretations of the findings and justifications for conclusions. This ensures that the analysis is thorough and can withstand scrutiny. Therefore, option D (all of these) is the best choice.

Question 8

Which of the following is not a major stage of data analysis?
A) getting to know the data
B) confirming what the data reveal
C) transforming the data
D) summarizing the data

Accepted Answer

The answer of Which of the following is not a...

Question 9

Computer-assisted data analysis requires that the researcher have a good knowledge of
A) null hypothesis testing.
B) research design and statistics.
C) computer hardware.
D) computer software.

Accepted Answer

Computer-assisted data analysis involves using software to handle data analysis tasks. However, the software cannot replace the researcher's knowledge of research design and statistics. Therefore, a good knowledge of research design and statistics is essential for successful computer-assisted data analysis. The other options, computer hardware and software may be important but are not as critical as the researcher's knowledge of statistics and research design.

Question 10

What does the "95" in a 95% confidence interval refer to?

Accepted Answer

The answer of What does the "95" in a 95%...

Question 11

An advantage of a stem-and-leaf display is that
A) it is a graph of the mean, median, and mode.
B) it reveals whether the relationship between two variables is linear.
C) it reveals the shape of a distribution and the presence of any outliers.
D) the intervals tells us how well our sample mean estimates the population mean.

Accepted Answer

A stem-and-leaf display is a method of organizing data where the digits in each value are separated into the stem and the leaf. The stem is typically the largest place value digit(s) while the leaf is the smallest. This display can quickly reveal the shape of a distribution and the presence of any outliers, making it useful for exploratory data analysis. It does not reveal whether the relationship between two variables is linear or provide information about the mean, median, and mode. While the stem-and-leaf display does show the range of the data, it does not provide enough information to estimate the population mean.

Question 12

The mean of a random sample of scores is a point estimate of
A) the center of a distribution.
B) standard error of the mean.
C) the population mean.
D) population variability.

Accepted Answer

The mean of a random sample of scores is a point estimate of the population mean.

Question 13

Describe the advantages and disadvantages of the three measures of central tendency: mean,median,mode.

Accepted Answer

The answer of Describe the advantages and disadvantages of the...

Question 14

If a stem-and-leaf display were created for the following set of numbers,23,24,24,21,20,27,29,28,we would expect the digit 2 to be a
A) leaf.
B) stem.
C) tree.
D) trunk.

Accepted Answer

In a stem-and-leaf display, the digits to the left of the rightmost digit form the stem and the rightmost digit forms the leaf. In this set of numbers, the stem would be the tens digit, which is 2. Therefore, the digit 2 would be the stem.

Question 15

Why is a confidence interval also called a "margin of error"?

Accepted Answer

The answer of Why is a confidence interval also called...

Question 16

The estimated standard error of the mean is equal to the sample ______ divided by _______.
A) variance; N
B) standard deviation; N - 1
C) standard deviation; N
D) standard deviation; $ \surd$N

Accepted Answer

The estimated standard error of the mean is calculated by dividing the sample standard deviation by the square root of the sample size (N).

Question 17

The value that splits a frequency distribution into two halves,each half with the same number of values,is the
A) mode.
B) mean.
C) median.
D) standard deviation.

Accepted Answer

The median is the value that divides a frequency distribution into two equal halves, meaning that half of the values are below the median and half are above it.

Question 18

The ____________ is the best measure of central tendency when there are extreme values in the distribution.
A) mode
B) median
C) mean
D) variance

Accepted Answer

The median is the best measure of central tendency when there are extreme values as it is less affected by outliers than the mean. The mean is influenced by extreme values and therefore may not be a good representation of the central tendency in such cases. The mode is not affected by extreme values but it may not accurately represent the true central tendency of the distribution. Variance is a measure of spread and not central tendency.

Question 19

Which of the following procedures would not be expected during the first stage of data analysis?
A) performing tests using inferential statistics
B) looking for outliers
C) visualizing the distribution with graphical displays
D) checking for errors

Accepted Answer

During the first stage of data analysis, you are primarily concerned with getting an overview of the data and checking for errors or issues. Performing tests using inferential statistics would be a more advanced technique that would be used later in the analysis process. The other options (B, C, and D) are all expected procedures during the first stage of data analysis.

Question 20

What does the width of a confidence interval tell us,and how does the size of a sample affect the width of a confidence interval for a population mean?

Accepted Answer

The answer of What does the width of a confidence...

Quiz 11: Data Analysis and Interpretation: Part Idescribing Data, confidence Intervals, correlation

Explain the phrase,"Correlation does not imply causation."

The most commonly used measure of central tendency is the

Which of the following is not a measure of dispersion or variability?

A score that is extreme and does not "go with" other scores in the distribution is called an

Distributions of scores for two groups in an experiment can be compared by

The standard deviation is equal to the square root of

A coherent "story" of data analysis for a study will include

Which of the following is not a major stage of data analysis?

Computer-assisted data analysis requires that the researcher have a good knowledge of

What does the "95" in a 95% confidence interval refer to?

An advantage of a stem-and-leaf display is that

The mean of a random sample of scores is a point estimate of

Describe the advantages and disadvantages of the three measures of central tendency: mean,median,mode.

If a stem-and-leaf display were created for the following set of numbers,23,24,24,21,20,27,29,28,we would expect the digit 2 to be a

Why is a confidence interval also called a "margin of error"?

The estimated standard error of the mean is equal to the sample divided by _.

The value that splits a frequency distribution into two halves,each half with the same number of values,is the

The ____________ is the best measure of central tendency when there are extreme values in the distribution.

Which of the following procedures would not be expected during the first stage of data analysis?

What does the width of a confidence interval tell us,and how does the size of a sample affect the width of a confidence interval for a population mean?