flc pysch 330 chapter 3 vocab

The _____ is the point in the distribution of scores that divides the distribution into two equal parts.

median

The mode is the most appropriate measure of central tendency when the scale of measurement used is

nominal

The _____ is the highest score minus the lowest score.

range

What measure of variability is most appropriate for interval/ratio data?

standard deviation

SS is the ________.

sum of squared deviations from the mean

Eight psychology students took a well-known I.Q. test and achieved the following scores: 96, 98, 108, 110, 115, 120, 121, 142. The median score for these students is ________.

112.50

After giving a test to all members of his college class, a professor found that the scores totaled 1500 and the mean was 75. How many students took the test?

20

Compute the sum of squares for the following data set: 2, 2, 3, 6, 9, 13, 14.

22.29

It has been reported the mean driving speed in California is 70 mph and the variance is 9. What is the SD?

3

The average person can hold 7+2 digits or bits of information in their short term memory with an SD= 2. What is the variance?

4

For the following set of scores compute the mean: 30 32 34 40 50 45 46 47

40.50

For the following set of scores compute the variance: 30 32 34 40 50 45 46 47

51

Given the data set 8, 8, 8, 7, 5, 6, 2, 2, what is the range?

6

A teacher wants to determine the mean score of students taking a newly developed test. Her students scored as follows: 40, 45, 60, 65, 70, 70, 70, 80, 90, 100. Compute the mean for the class.

69

Which of the following statements is true of a median score

Both of the above descriptors are true.

Range

Highest scores minus the lowest score.

Measures of Central Tendency:

Indicate what the typical score in a data set is. Measures of central tendency include the mode, median, and mean.

Descriptive Statistics:

Numerical indices that describe either a population or a sample.

Negative Skew:

Occurs when most scores are at the high end of a distribution

Positive Skew:

Occurs when most scores are at the low end of a distribution

Measures of Variability:

Provide an index of the amount of spread or dispersion among a set of scores. Measures of variability also indicate how similar the scores are. Measures of variability include the range, sum of squares, variance, and standard deviation.

Mean:

The arithmetic average score in a distribution.

Variance

The average amount a set of scores deviates from the mean in squared units.

Standard deviation:

The average amount a set of squares deviates from the mean

Median

The point in the distribution above and below which 50% of the scores fall. The median is the score at the 50th percentile.

Mode

The score in a distribution that has the highest frequency or occurs most often. Median: The point in the distribution above and below which 50% of the scores fall. The

Skew:

The tendency for scores to cluster on one side of the mean (versus a non-skewed distribution, in which the scores are equally distributed around the mean).

Sum of squares:

The total amount a set of scores deviates from the mean in squared units

The mean is computed by summing all of the scores and then dividing the sum by the:

all of the above

The variance is the

average of the squared deviations from the mean

In positively skewed distributions, most scores occur _____ the mean and only a relatively few extreme scores occur _____ it.

below; above

Measures of Central tendency are an example of_______

descriptive statistics

The _____ is the difference between the highest and lowest scores after the top 25% of the scores and the bottom 25% of the scores have been eliminated from the data.

interquartile range

The interquartile range is sometimes preferred over the range because it

is not influenced by extreme scores

The best answer to the question, "What value indicates a large standard deviation?" is:

it depends on what is being measured

Most of the inferential statistics used by behavioral scientists make use of the ___ as a measure of central tendency.

mean

The _____ is the measure of central tendency that is most sensitive to extreme values in a distribution.

mean

What measure of central tendency is most appropriate for interval/ratio data?

mean

The range indicates

the distance between the highest and lowest score

The major problem with the mode as a measure of central tendency is that:

there can be more than one modal score

Measures of _____ indicate the extent to which scores within a set differ from one another.

variability