Finding the Fourth Proportional to 1,380.72, 2,071.39 and 731.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.72 : 2,071.39 = 731.91 : x
2. Step 2: Convert to fraction form
   1,380.72/2,071.39 = 731.91/x
3. Step 3: Cross multiply
   1,380.72x = 2,071.39 × 731.91
4. Step 4: Simplify right side
   1,380.72x = 1,516,071.05
5. Step 5: Solve for x
   x = 1,516,071.05/1,380.72
6. Step 6: Final answer
   x = 1,098.03