Think about the values that the given variables can take.
y, natural numbers
p, rational numbers
Before we consider the given variables, let's recall the various types of numbers.
Rational Number: A number is a rational number if it can be written in the form ab, where a and b are both integers and b≠0.
Integer: A number is an integer if it is a positive or negative counting number (or zero). All integers are also rational numbers because any number can be written as a division by one, a1.
Whole Number: A number is a whole number if it is a non-negative counting number. All whole numbers are also integers and rational numbers.
Natural Number: A number is a natural number if it is a positive counting number. All natural numbers are also whole numbers, integers, and rational numbers.
Irrational Number: An irrational number is a number that cannot be written in the form of a rational number. These are recognized as being non-repeating, infinite decimals.
Now let's consider the given variables by thinking about the values they can take.
the year y
the median selling price p for a house that year
Consider the year 2019. To find other years, we either add 1 repeatedly or subtract 1 repeatedly from 2019. Years are also positive and there is not a year 0. Therefore, y is included in the set of natural numbers. To determine the set in which p belongs, we will consider two cases.
