Describing Single Variables

What does the term 'descriptive statistics' refer to?

According to the text, what is the 'distribution' of a variable?

What is one way to display the distribution of a variable, as shown in the hypothetical distribution of scores on the Rosenberg Self-Esteem Scale?

When creating a grouped frequency table where the first column lists ranges of values, what is a key rule regarding the ranges?

What is a histogram?

In a histogram for a quantitative variable, what is the typical presentation of the vertical bars?

A distribution that has two distinct peaks is known as what?

What is the characteristic of a negatively skewed distribution?

An extreme score that is much higher or lower than the rest of the scores in a distribution is called what?

What does the 'central tendency' of a distribution describe?

What is the mean of a distribution?

For the following set of seven scores: 8, 4, 12, 14, 3, 2, 3, what is the median?

If a dataset has an even number of scores, how is the median determined?

Which measure of central tendency is the only one that can be used for categorical variables?

In a distribution that is both unimodal and symmetrical, what is the relationship between the mean, median, and mode?

For highly skewed distributions, why do researchers often prefer the median over the mean?

What does the 'variability' of a distribution describe?

What is the simplest measure of variability, calculated as the difference between the highest and lowest scores?

A set of self-esteem scores has a highest score of 24 and a lowest score of 15. What is the range of this distribution?

Why can the range be a misleading measure of variability?

What is the most common measure of variability, representing the average distance between the scores and the mean?

What is the variance (symbolized SD squared)?

For a set of eight scores with a mean of 5, the sum of the squared differences from the mean is 28. What is the variance (SD squared)?

Why do most calculators and software packages divide the sum of squared differences by N-1 instead of N when computing the standard deviation?

What does the 'percentile rank' of a score represent?

In a distribution of 40 scores, a particular score is higher than 32 of the scores. What is the percentile rank of this score?

What is the formula for calculating a z-score?

In a distribution of IQ scores with a mean of 100 and a standard deviation of 15, what is the z-score for an individual with an IQ of 110?

How does the text suggest that outliers are sometimes defined using z-scores?

What is the primary focus of descriptive statistics as described in Chapter 52?

For the following scores: 2, 3, 3, 4, 8, 12, 14, what is the mode?

What is the key advantage of a histogram over a frequency table?

What is the shape of a distribution where its left and right halves are mirror images of each other?

In a positively skewed distribution, how does the mean typically relate to the median?

For the following set of eight scores: 2, 3, 3, 4, 8, 12, 14, 15, what is the median?

In a hypothetical distribution of self-esteem scores, the most frequent score is 22. Which measure of central tendency does 22 represent?

The formula M = ΣX/N is used to calculate which measure of central tendency?

What is the standard deviation?

For a set of eight scores with a mean of 5, the variance is 3.50. What is the standard deviation?

A z-score indicates how far above or below the mean a raw score is, expressed in terms of what unit?

A person's score on a test of verbal ability has a percentile rank of 40. What does this indicate?

A raw score of 85 in a distribution with a mean of 100 and a standard deviation of 15 has a z-score of what?

What is another term for central tendency mentioned in the text?

What are the three most common measures of central tendency discussed in the chapter?

What is a major reason that the mean is the most common measure of central tendency?

In a bimodal distribution, where will the mean and median tend to be located?

Two distributions have the same mean, median, and mode of 10. The first has a standard deviation of 1.69 and the second has a standard deviation of 4.30. What does this difference in standard deviation indicate?

In the process of computing the standard deviation, the differences between each score and the mean are squared. Why is this done?

What is the primary information provided by a z-score for a given raw score?

When creating a grouped frequency table, the text suggests there should usually be how many ranges (or groups)?