第4问

income_df.describe()

income_df['Training program'].value_counts()

income_df['age'].value_counts()

income_df['educ'].value_counts()

income_df['income_74'].value_counts()

income_df['income_75'].value_counts()

income_df['income_76'].value_counts()

income_df['nodeg'].value_counts()

income_df['race'].value_counts()

income_df['status'].value_counts()

income_df['unemployment'].value_counts()