Finding the Fourth Proportional to 1,381.25, 1,906.07 and 783.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,381.25 : 1,906.07 = 783.72 : x
2. Step 2: Convert to fraction form
   1,381.25/1,906.07 = 783.72/x
3. Step 3: Cross multiply
   1,381.25x = 1,906.07 × 783.72
4. Step 4: Simplify right side
   1,381.25x = 1,493,821.26
5. Step 5: Solve for x
   x = 1,493,821.26/1,381.25
6. Step 6: Final answer
   x = 1,081.50