Finding the Fourth Proportional to 1,553.39, 2,144.09 and 915.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,553.39 : 2,144.09 = 915.89 : x
2. Step 2: Convert to fraction form
   1,553.39/2,144.09 = 915.89/x
3. Step 3: Cross multiply
   1,553.39x = 2,144.09 × 915.89
4. Step 4: Simplify right side
   1,553.39x = 1,963,742.16
5. Step 5: Solve for x
   x = 1,963,742.16/1,553.39
6. Step 6: Final answer
   x = 1,264.17