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America's Melting Pot. The U.S. Census Bureau publishes data on the population of the United States by race and Hispanic origin in American Community Survey. From that document, we constructed the following bar chart. Note that people who are Hispanic may be of any race, and people in each race group may be either Hispanic or not Hispanic.

a. Explain why a break is shown in the first bar.

b. Why was the graph constructed with a broken bar?

c. Is this graph potentially misleading? Explain your answer.

The Federal Reserve System publishes weekly figures for M2 money supply in the document Money Stock Measures. M2 includes such things as cash in circulation, deposits in checking accounts, nonbank traveller's checks, accounts such as savings deposits, and money-market mutual funds. The following bar chart provides data on the M2 money supply over $3$months during one year.

a. What is wrong with the bar chart?

b. Construct a version of the bar chart with a nontruncated and unmodified vertical axis.

c. Construct a version of the bar chart in which the vertical axis is modified in an acceptable manner.

What is the frequency distribution of qualitative data and why is it useful?

Explain the difference between

a. frequency and relative frequency.

b. percentage and relative frequency.

Answer true or false to each of the statements in parts (a) and (b), and explain your reasoning.

a. Two data sets that have identical frequency distributions have identical relative-frequency distributions.

b. Two data sets that have identical relative-frequency distributions have identical frequency distributions.

c. Use your answers to parts (a) and (b) to explain why relative frequency distributions are better than frequency distributions for comparing two data sets.

Explain the meaning of

a) Qualitative Variable

b) Discrete, Quantitative Variable

c) Continuous, Quantitative Variable

In Exercises 2.20-2.25, we have presented some simple qualitative data sets for practicing the concepts. For each data set,

a. determine a frequency distribution.

b. obtain a relative-frequency distribution.

c. draw a pie chart.

d. Construct a bar chart.

In Exercises 2.20-2.25, we have presented some simple qualitative data sets for practicing the concepts. For each data set,

a. determine a frequency distribution.

b. obtain a relative-frequency distribution.

c. draw a pie chart.

d. Construct a bar chart.

Class Levels. Earlier in this section, we considered the political party affiliations of the students in Professor Weiss's introductory statistics course. The class levels of those students are as follows, where Fr, So, Jr, and Sr denote freshman, sophomore, junior, and senior, respectively.

Explain the meaning of

Qualitative Variable

Discrete, Quantitative Variable

Continuous, Quantitative Variable