Frequency Distributions And Their Graphs

Question 1

Class Boundaries

Answer 1

The numbers that separate cases without forming gas between them.
Subtract 0.5 for each lower limit
Add 0.5 for each upper limit.

Question 2

Class Limits

Answer 2

2 types of limits
1. Lower class limit: least number that can belong in a class
2. Upper class limit: greatest number that can belong to a class.

Question 3

Class Midpoints

Answer 3

Is the sum of the lower and upper limits of the class divided by 2.
Sometimes called the class mark.
(LL) + (UL) / 2 = midpoint

Question 4

Cumulative Frequency

Answer 4

Is the sum of the frequencies of that class and all previous classes.
The cumulative frequency of the last class is equal to the sample size n.

Question 5

Relative Frequency

Answer 5

Is the portion, or percentage of the data that falls in that class.
Class frequency/sample size = RF
Or f/n

Question 6

Frequency Distribution

Answer 6

Is a table that showed classes or intervals of data entries with a count of the number of entries in each class.
The frequency f of a class is the number of data entries in the class.

Question 7

Frequency Histogram

Answer 7

Uses bars to represent the frequency distribution of a data set.
Has the following properties:
1. Horizontal scale is quantitative and measures the data entries.
2. Vertical scale measures the frequencies of the classes.
3. Consecutive bars must touch.

Question 8

Relative Frequency Histograms

Answer 8

Has the same shape and the same scale as the corresponding frequency histogram.
The difference is that the vertical scale measures the relative frequencies, not frequencies.

Question 9

Frequency Polygon

Answer 9

Is a line graph that emphasizes the continues change in frequencies.

Question 10

Ogive or Cumulative Frequency Graph

Answer 10

Is a line graph that displays cumulative frequency of each class at its upper limit boundary.
The upper limits are marked on the H axis and the cumulative frequencies are marked on the vertical axis.