Finding the Fourth Proportional to 10,915.10, 15,315.70 and 10,915.10

Step by Step Solution

1. Step 1: Write the proportion equation
   10,915.10 : 15,315.70 = 10,915.10 : x
2. Step 2: Convert to fraction form
   10,915.10/15,315.70 = 10,915.10/x
3. Step 3: Cross multiply
   10,915.10x = 15,315.70 × 10,915.10
4. Step 4: Simplify right side
   10,915.10x = 167,172,397.07
5. Step 5: Solve for x
   x = 167,172,397.07/10,915.10
6. Step 6: Final answer
   x = 15,315.70