Finding the Fourth Proportional to 1,380.96, 1,905.90 and 849.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.96 : 1,905.90 = 849.72 : x
2. Step 2: Convert to fraction form
   1,380.96/1,905.90 = 849.72/x
3. Step 3: Cross multiply
   1,380.96x = 1,905.90 × 849.72
4. Step 4: Simplify right side
   1,380.96x = 1,619,481.35
5. Step 5: Solve for x
   x = 1,619,481.35/1,380.96
6. Step 6: Final answer
   x = 1,172.72