Section 7: Shapes of Distributions

A frequency polygon is

a drawing that shows how many participants have each score.

A frequency distribution is

a table that shows how many participants have each score.

A distribution with a negative skew has

a tail to the left.

A distribution with a positive skew has

a tail to the right.

What is the name of the type of distribution that has two high points?

Bimodal.

What is the name of a table that shows how many participants have each score?

Frequency distribution.

What does a frequency polygon show?

How many participants have each score.

In a distribution with a negative skew, is the long tail pointing to the "left" or the "right"?

Left.

Suppose that on a 100-item multiple-choice test, almost all students scored between 95 and 100 but a small scattering scored as low as 20. When plotted as a curve, the distribution will show what type of skew?

Negative.

What is the most important type of curve?

Normal.

Suppose that a broad cross section of high school students took a very different scholarship examination and almost all scored very low, but a very small number scored very high. When plotted as a curve, the distribution will show what type of skew?

Positive.

When plotted, income in late populations usually has what type of skew?

Positive.

Which type of distribution is often found in nature?

The normal curve.

Which type of distribution is found much less frequently in research than the others?

bimodal.

The shape of the distribution has

implications for determining which average to compute.

The normal curve is

the most important curve.

A bimodal distribution has

two high points.