Question 1

With respect to standard deviation, which of the following statements is not correct?
A) the total deviation is zero
B) the average deviation is zero
C) the value can range from negative 1 to positive 1
D) the sum of the deviations from the mean will always be zero

Accepted Answer

The statement that standard deviation can range from negative 1 to positive 1 is not correct. Standard deviation is a measure of dispersion of a set of data from its mean and can take any positive value depending on the spread of data. It is not limited to a range of -1 to 1.

Question 2

While the linear regression model is important for descriptive purposes, its predictive value is limited.

Accepted Answer

Linear regression models are widely used for both descriptive and predictive purposes. They can effectively predict outcomes based on the linear relationship between the dependent and independent variables.

Question 3

Which of the following would represent a distribution of those arrested on a holiday weekend?
A) the exact number of persons arrested for violation of specific statute numbers
B) a list of persons arrested with the corresponding statute number they allegedly violated
C) the number of persons arrested for violent crimes, the number of persons arrested for property crimes, and the number of persons arrested for public order crimes
D) all of the above

Accepted Answer

Each option represents a different way to categorize or detail the distribution of arrests over a holiday weekend, encompassing specific violations, individual cases, and broader crime categories.

Question 4

Bivariate analyses typically have an explanatory purpose.

Accepted Answer

Bivariate analyses aim to examine the relationship or association between two variables, which often involves explaining how one variable affects the other. Therefore, the purpose of bivariate analyses is usually explanatory.

Question 5

Because extremes in a distribution (a very large or very small number) can impact the mean, it is usually important to examine measures of dispersion about the mean.

Accepted Answer

This statement is true. Measures of dispersion, such as variance and standard deviation, give insight into how spread out the data is around the mean and can help identify outliers or extreme values.

Question 6

In univariate analysis, missing data can be reported in several different ways.

Accepted Answer

In univariate analysis, missing data can be reported in several ways such as through frequencies, percentages, or even a separate category for missing data.

Question 7

Which of the following measures of central tendency are the easiest to calculate?
A) mean
B) mode
C) standard deviation
D) median

Accepted Answer

The mode, which is simply the most frequently occurring value in a data set, is generally the easiest measure of central tendency to calculate because it does not require any complex operations or ordering of the data.

Question 8

To calculate the mean for grouped data, which of the following steps should not be completed?
A) multiply the number of subjects within each category by the value of that category
B) total the results of the multiplication
C) divide by the number of categories
D) divide by the number of subjects

Accepted Answer

To calculate the mean for grouped data, you should not divide by the number of categories. Instead, after multiplying the number of subjects within each category by the value of that category and totaling the results, you divide by the total number of subjects to find the mean.

Question 9

Summary statistics, or measures of central tendency, include the mode, mean, and median.

Accepted Answer

Summary statistics, or measures of central tendency, do include the mode, mean, and median.

Question 10

Measures of central tendency include all except:
A) standard deviation
B) median
C) mean
D) mode

Accepted Answer

Standard deviation is a measure of variability, not central tendency. The other options (median, mean, mode) are all measures of central tendency.

Question 11

Dr. Jones wanted to display the findings of the sentences given in his local courthouse on one summer day. If the sentences, displayed in months, were 10, 18, 24, 36, 18, 70, 30, then which of the following measures of central tendency is accurate?
A) the mean is 24
B) the median is 24
C) the mode is 24
D) mean, median, and mode are the same

Accepted Answer

To find the median, we need to arrange the numbers in order from least to greatest: 10, 18, 18, 24, 30, 36, 70. Then, we can see that the middle number is 24, which is the median. The mean can be calculated by adding up all the numbers and dividing by the total number of numbers, which gives (10+18+18+24+30+36+70)/7 = 28. Therefore, the median is a better measure of central tendency because it is not affected by extreme values, such as the 70 in this data set. The mode, which is the most frequently occurring number, is not 24, but 18.

Question 12

With respect to standard deviation, which of the following statements is correct?
A) it is based on the squared deviations from the mean
B) it is the square of the variance
C) it is always a negative number
D) all of the above

Accepted Answer

Standard deviation is based on the squared deviations from the mean. Option B is incorrect because variance is the squared standard deviation, not the other way around. Option C is incorrect because standard deviation can never be negative. Therefore, only option A is correct.

Question 13

The range is a measure of central tendency.

Accepted Answer

The range is not a measure of central tendency, but rather a measure of variability or dispersion in a set of data. Measures of central tendency include the mean, median, and mode.

Question 14

Of the three measures of central tendency, which one is affected by extreme values?
A) mode
B) median
C) mean
D) neither mode, median, or mean are affected by extreme values

Accepted Answer

The mean is calculated by adding up all the values in a data set and dividing by the total number of values. This means that extreme values, or outliers, can greatly influence the value of the mean. The mode and median are not affected by extreme values because they only consider the most common or middle value(s) in the data set, respectively.

Question 15

When reporting marginals for univariate analysis, the presentation must be in raw numbers and cannot be reported in percentages.

Accepted Answer

Marginals for univariate analysis can be reported in both raw numbers and percentages. It is often useful to present both to provide a more comprehensive understanding of the data.

Question 16

Tests of statistical significance should only be used when the relationships observed in data collected come from the whole population.

Accepted Answer

Tests of statistical significance can be used to infer relationships from a sample to a population, but they cannot guarantee that the relationships observed in the sample also exist in the population. Therefore, they can be used to make inferences about the population with some degree of uncertainty.

Question 17

Empirical research is first a logical rather than a mathematical operation.

Accepted Answer

Empirical research involves gathering data through observation and experimentation, which can be analyzed using statistical methods, but the initial process of designing and planning the research is based on logical reasoning rather than mathematical computation.

Question 18

Which of the following is not accurate concerning empirical research?
A) empirical research is a logical rather than a mathematical operation
B) mathematics is a convenient and efficient language
C) statistics is the applied branch of mathematics
D) empirical research is free of validity problems

Accepted Answer

Empirical research is not free of validity problems, as these issues can arise due to a variety of factors such as sampling biases or measurement errors.

Question 19

Univariate analysis and subgroup comparisons focus on describing variables while bivariate analysis focuses upon people.

Accepted Answer

Univariate analysis and subgroup comparisons involve analyzing and describing variables, while bivariate analysis involves analyzing and describing the relationship between two variables. It is not necessarily focused on people specifically.

Question 20

Which of the following do not represent measures of dispersion?
A) ranges
B) means
C) standard deviations
D) variation in groups

Accepted Answer

Means represent measures of central tendency, not measures of dispersion. Ranges, standard deviations, and variation in groups all represent measures of dispersion.

Quiz 14: Interpreting Data

With respect to standard deviation, which of the following statements is not correct?

While the linear regression model is important for descriptive purposes, its predictive value is limited.

Which of the following would represent a distribution of those arrested on a holiday weekend?

Bivariate analyses typically have an explanatory purpose.

Because extremes in a distribution (a very large or very small number) can impact the mean, it is usually important to examine measures of dispersion about the mean.

In univariate analysis, missing data can be reported in several different ways.

Which of the following measures of central tendency are the easiest to calculate?

To calculate the mean for grouped data, which of the following steps should not be completed?

Summary statistics, or measures of central tendency, include the mode, mean, and median.

Measures of central tendency include all except:

Dr. Jones wanted to display the findings of the sentences given in his local courthouse on one summer day. If the sentences, displayed in months, were 10, 18, 24, 36, 18, 70, 30, then which of the following measures of central tendency is accurate?

With respect to standard deviation, which of the following statements is correct?

The range is a measure of central tendency.

Of the three measures of central tendency, which one is affected by extreme values?

When reporting marginals for univariate analysis, the presentation must be in raw numbers and cannot be reported in percentages.

Tests of statistical significance should only be used when the relationships observed in data collected come from the whole population.

Empirical research is first a logical rather than a mathematical operation.

Which of the following is not accurate concerning empirical research?

Univariate analysis and subgroup comparisons focus on describing variables while bivariate analysis focuses upon people.

Which of the following do not represent measures of dispersion?