Finding the Fourth Proportional to 1,402.80, 2,105.04 and 915.84

Step by Step Solution

1. Step 1: Write the proportion equation
   1,402.80 : 2,105.04 = 915.84 : x
2. Step 2: Convert to fraction form
   1,402.80/2,105.04 = 915.84/x
3. Step 3: Cross multiply
   1,402.80x = 2,105.04 × 915.84
4. Step 4: Simplify right side
   1,402.80x = 1,927,879.83
5. Step 5: Solve for x
   x = 1,927,879.83/1,402.80
6. Step 6: Final answer
   x = 1,374.31