The Shape of Distributions

Question 1

Frequency Distribution

Answer 1

A table or graph that indicates how many times a value or score appears in a set of values or scores.

Question 2

Negative Skew

Answer 2

The shape of a distribution that includes some extremely low scores or values. A distribution is said to have a negative skew if the tail of the distribution points toward the left.

Question 3

Normal Curve

Answer 3

A unimodal, symmetrical curve that is mathematically defined on the basis of the mean and standard deviation of an underlying distribution.

Question 4

One-Two-Three Rule

Answer 4

A statement of how much area under a normal curve is found between +1, +2, and +3 standard deviations from the mean.

Question 5

Point of Inflection

Answer 5

The point at which a normal curve begins to change direction. It is one standard deviation above or below the mean of the underlying distribution.

Question 6

Positive Skew

Answer 6

The shape of a distribution that includes some extremely high scores or values. A distribution is said to have a positive skew if the tail of the distribution points toward the right.

Question 7

Skewed Distribution

Answer 7

A unimodal distribution that departs from symmetry, in the sense that most of the cases are concentrated at one end of the distribution.

Question 8

Symmetrical Distribution

Answer 8

A distribution in which the two halves are mirror images of each other.

Question 9

Tail Distribution

Answer 9

In a skewed distribution, the elongated portion of the curve.