Answer:
all of them are REAL numbers
1. is also RATIONAL
2. is also IRRATIONAL
3. is also IRRATIONAL
4. is also NATURAL, WHOLE, INTEGER and RATIONAL
5. is also INTEGER and RATIONAL
6. incorrect, because integer is just the whole numbers extended by their additive counterparts (the negative natural numbers). in other words, their absolute values are whole numbers. 5.5 as well as -5.5 are not fitting that criteria.
7. incorrect, because this pattern does not fit the definition of a radical number, where the number eventually begins to repeat the same finite sequence of digits over and over. in this example the pattern is not based on a finite sequence of digits.
