Finding the Fourth Proportional to 2,086.62, 3,127.32 and 915.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.62 : 3,127.32 = 915.90 : x
2. Step 2: Convert to fraction form
   2,086.62/3,127.32 = 915.90/x
3. Step 3: Cross multiply
   2,086.62x = 3,127.32 × 915.90
4. Step 4: Simplify right side
   2,086.62x = 2,864,312.39
5. Step 5: Solve for x
   x = 2,864,312.39/2,086.62
6. Step 6: Final answer
   x = 1,372.70