CHPT 2.1 FREQUENCY DISTRIBUTIONS

Midpoint

(Lower class limit)+(Upper class limit)/2

When constructing a relative frequency distribution, what should be the sum of the relative​ frequencies?

If percentages are​ used, the sum should be​ 100%. If proportions are​ used, the sum should be 1.

Why should the number of classes in a frequency distribution be between 5 and​ 20?

If the number of classes in a frequency distribution is not between 5 and​ 20, it may be difficult to detect any patterns.

What is the difference between relative frequency and cumulative​ frequency?

Relative frequency of a class is the percentage of the data that falls in that​ class, while cumulative frequency of a class is the sum of the frequencies of that class and all previous classes

How to find class width

max-min/# of classes

Class width

the distance between the lower or upper limits of consecutive classes.

What are some benefits of using graphs of frequency​ distributions?

It can be easier to identify patterns of a data set by looking at a graph of the frequency distribution.

How to find upper class limits

Lower class limits - 1

How to find lower class limits

Lowest data value +Class width

What is the difference between class limits and class​ boundaries?

Class limits are the least and greatest numbers that can belong to the class. Class boundaries are the numbers that separate classes without forming gaps between them. For integer​ data, the corresponding class limits and class boundaries differ by 0.5.

What are some benefits of representing data sets using frequency​ distributions?

Organizing the data into a frequency distribution can make patterns within the data more evident.

What is the difference between a frequency polygon and an​ ogive?

A frequency polygon displays class frequencies while an ogive displays cumulative frequencies.