Final answer:
The cardinal number of the set x = k³, k = 1, 2, 3, ..., 98 is 98, because it includes 98 unique cube numbers corresponding to each integer value of k from 1 to 98.
Step-by-step explanation:
The student's question asks for the cardinal number of the set defined by x . To find the cardinal number, which represents the size of the set, we count the number of unique elements fulfilling the condition. Since each k leads to a unique k³, and the values of k are sequential integers from 1 to 98, the cardinal number is simply the count of numbers from 1 to 98.
Therefore, the cardinal number of the set is 98, because there are 98 unique values of k when k ranges from 1 to 98.