Yes, 9/373 is a repeating decimal.
To understand why, let’s look at the division of 9 by 373. When you perform long division, you’ll find that the division does not terminate as a finite decimal. Instead, the remainders will eventually start to repeat, leading to a decimal representation that goes on infinitely.
In general, a fraction will result in a repeating decimal if the denominator (after removing any factors of 2 and 5) has prime factors other than 2 or 5. Since 373 is a prime number that is not 2 or 5, 9/373 qualifies as a repeating decimal.