Finding the Fourth Proportional to 1,378.55, 1,902.69 and 906.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.55 : 1,902.69 = 906.86 : x
2. Step 2: Convert to fraction form
   1,378.55/1,902.69 = 906.86/x
3. Step 3: Cross multiply
   1,378.55x = 1,902.69 × 906.86
4. Step 4: Simplify right side
   1,378.55x = 1,725,463.94
5. Step 5: Solve for x
   x = 1,725,463.94/1,378.55
6. Step 6: Final answer
   x = 1,251.66