Finding the Fourth Proportional to 1,357.92, 1,871.75 and 915.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,357.92 : 1,871.75 = 915.05 : x
2. Step 2: Convert to fraction form
   1,357.92/1,871.75 = 915.05/x
3. Step 3: Cross multiply
   1,357.92x = 1,871.75 × 915.05
4. Step 4: Simplify right side
   1,357.92x = 1,712,744.94
5. Step 5: Solve for x
   x = 1,712,744.94/1,357.92
6. Step 6: Final answer
   x = 1,261.30