MTH245 Ch 2

What is the difference between class limits and class boundaries?

Class limits determine which numbers can belong to that class. Class boundaries are the numbers that separate classes without forming gaps between them.

True or False? If it is false, rewrite it as a true statement. In a frequency distribution, the class width is the distance between the lower and upper limits of a class.

False. Class width is the difference between the lower (or upper limits) of consecutive classes連続したクラス.

What are some benefits of using graphs of frequency distributions?

If there are too few or too many classes, it may be difficult to detect patterns because the data are too condensed or too spread out.

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

Organizing the data into a frequency distribution may make patterns within the data more evident. Sometimes it is easier to identify patterns of a data set by looking at a graph of the frequency distribution.

After constructing an expanded frequency distribution, what should the sum of the relative frequencies be? Explain.

The sum of the relative frequencies must be 1 or 100% because it is the sum of all portions or percentages of the data.

True or False? If it is false, rewrite it as a true statement. The midpoint of a class is the sum of its lower and upper limits divided by two.

True

What is the difference between relative frequency and cumulative frequency?

Relative frequency of a class is the portion, or percentage, of the data that falls in that class. Cumulative frequency of a class is the sum of the frequencies of that class and all previous classes.

What is the difference between a frequency polygon and an ogive累積度数分布図?

A frequency polygon displays frequencies or relative frequencies whereas an ogive displays cumulative frequencies.