In General Terms, Which of the Following Statements Regarding Changes

question 9

Multiple Choice

In general terms, which of the following statements regarding changes in income inequality in the United States is correct?

• A)Inequality has increased over the last 30 years as witnessed by the Gini coefficient increasing from about 0.1 in 1970 to about 0.7 in 2000.
• B)Inequality has increased over the last 30 years as witnessed by the Gini coefficient increasing from about 0.3 in 1970 to about 0.45 in 2000.
• C)Inequality has decreased over the last 30 years as witnessed by the Gini coefficient decreasing from about 0.5 in 1970 to about 0.05 in 2000.
• D)Inequality has decreased over the last 30 years as witnessed by the Gini coefficient decreasing from about 0.8 in 1970 to about 0.25 in 2000.
• E)Inequality has stayed about the same over the last 30 years as witnessed by a Gini coefficient that has hovered around 0.6.

Understand the concept of confidence intervals and their calculation, including the role of t-distribution.

Recognize the properties and significance of the t-distribution in statistical analysis.

Apply the concept of degrees of freedom in t-distribution calculations.

Identify conditions under which confidence intervals for population means can be constructed.