GRAVETTER_CH02_FREQUENCY DISTRIBUTION GRAPHS Flashcards
What is the term for the X-axis?
The abscissa
What is the term for the y-axis?
The ordinate
TRUE OR FALSE: A rule in constructing graphs is that the X-axis is longer than the Y-axis.
TRUE.
A general rule is that the height (y-axis) is approx. two-thirds to three-quarters of its length (x-axis). V
The measurement scale is which axis?
X-axis
The frequencies are along which axis?
Y-axis.
What are the two options for constructing a FDG?
Histograms and polygons.
TRUE OR FALSE: Histograms and polygons are used for interval and ratio scales.
TRUE.
TRUE OR FALSE: When the scores are measured on a nominal or ordinal scale (usually non-numerical values), the frequency distribution can be displayed in a bar graph.
TRUE.
TRUE OR FALSE: There is no meaning in how the bars are separated in a bar graph.
FALSE.
The space between the bars emphasizes that the scale consists of separate, distinct categories (for nominal scales). For ordinal scales, separate bars are used because you cannot assume that the categories are the same size.
What are the two “special features” of graphs showing frequency distributions for extremely large populations?
- Relative frequencies
2. Smooth curves
TRUE OR FALSE: Relative frequencies show exact values when providing data for a big sample.
FALSE.
Relative frequencies are used when you cannot find the absolute frequency for each score in a population (which is often). An example would be that no one knows the exact number of men and women living in the Philippines, because the number keeps changing.
Based on past data, however, as well as general trends, we can estimate and come up with a frequency distribution graph showing relative number, and not absolute number. We can at least see the ratio of men to women in cases like this.
THINK! What does the smooth curve imply, as compared to the jagged, step-wise shapes that occur with histograms and polygons?
The smooth curve indicates relative changes that occur from one score to the next.
THINK! What does the word “normal” mean?
The word “normal” refers to a specific shape that can be precisely defined by an equation.
In a _______ distribution, it is possible to draw a vertical line through the middle so that one side of the distribution is a mirror image of the other.
symmetrical
In a _______ distribution, the scores tend to pile up toward one end of the scale and taper off gradually at the other end.
skewed
