Final Answer:
The number 7 can be expressed as a fraction of two integers, making it a rational number. Therefore the correct option is b. rational number, 0.625
Step-by-step explanation:
The correct classification for the number 7 is a rational number with a decimal expansion of 0.625.
A rational number is any number that can be expressed as a fraction where the numerator and denominator are integers, and the denominator is not zero. The number 7 can be written as the fraction ( frac{7}{10} ), which is a ratio of two integers, making it a rational number.
The decimal expansion of 7 as a fraction is 0.7 when represented as a whole number. However, when considering 7 in the context of a fraction with a denominator of 10, it is written as 0.625.
This decimal expansion, 0.625, represents a rational number because it can be expressed as a quotient of two integers: 625/1000, which simplifies to ( frac{5}{8} ).
Hence, the number 7 is a rational number with a decimal expansion of 0.625, aligning with the definition of rational numbers as fractions of integers.
Therefore the correct option is b. rational number, 0.625