A recent study showed that an increase in body weight by 10 kilograms resulted in a 0.15% increase in heart disease. What fraction is equal to 0.15%?

0.15% can be converted to a fraction by following these steps:

1. First, understand that percent means "per 100", so 0.15% can be written as 0.15 per 100.

2. Write this as a fraction. So, 0.15% is the same as 0.15/100.

3. To simplify this fraction, we can remove the decimal from the numerator by multiplying both the numerator and the denominator by 10. This gives us 1.5/1000.

4. This fraction can be further simplified by dividing both the numerator and the denominator by the greatest common divisor. The greatest common divisor of 1.5 and 1000 is 1.5. So, divide 1.5 by 1.5 to get 1 and 1000 by 1.5 to get approximately 666.67.

So, 0.15% is approximately equal to the fraction 1/666.67. However, it's important to note that this is an approximation because 666.67 is not a whole number. If you want to express 0.15% as an exact fraction, it's best to leave it as 0.15/100 or 1.5/1000.