From the document "Computer and Internet Use in the United States: Population Characteristics" (Current Population Survey) by T. File, we obtained the following percentage distribution of household income for U.S. households with Internet access.

Suppose that a U.S. household with Internet access is selected at random. Let A denote the event that the household has an income under $25,000, B denote the event that the household has an income between $25,000 and $49,999, and so on (see the third column of the table). Apply the special addition rule to find the probability that the household obtained has an income
a. Under $50,000.
b. $25,000 or above.
c. Between $25,000 and $149,999, inclusive.
d. INTERPRET each of your answers in parts (a)-(c) in terms of percentages.

Household incoe ercentage Event Less than $25,000 $25,000-$49,999 $50,000-$99,999 $100,000 $149,999 $150,000 or more 17.1 24.0 35.0 14.1 9.8