Finding the Fourth Proportional to 1,381.10, 1,906.31 and 909.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,381.10 : 1,906.31 = 909.34 : x
2. Step 2: Convert to fraction form
   1,381.10/1,906.31 = 909.34/x
3. Step 3: Cross multiply
   1,381.10x = 1,906.31 × 909.34
4. Step 4: Simplify right side
   1,381.10x = 1,733,481.44
5. Step 5: Solve for x
   x = 1,733,481.44/1,381.10
6. Step 6: Final answer
   x = 1,255.15