Finding the Fourth Proportional to 1,008.84, 1,512.72 and 315.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,008.84 : 1,512.72 = 315.38 : x
2. Step 2: Convert to fraction form
   1,008.84/1,512.72 = 315.38/x
3. Step 3: Cross multiply
   1,008.84x = 1,512.72 × 315.38
4. Step 4: Simplify right side
   1,008.84x = 477,074.86
5. Step 5: Solve for x
   x = 477,074.86/1,008.84
6. Step 6: Final answer
   x = 472.90