Finding the Fourth Proportional to 1,395.49, 2,091.78 and 654.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,395.49 : 2,091.78 = 654.72 : x
2. Step 2: Convert to fraction form
   1,395.49/2,091.78 = 654.72/x
3. Step 3: Cross multiply
   1,395.49x = 2,091.78 × 654.72
4. Step 4: Simplify right side
   1,395.49x = 1,369,530.20
5. Step 5: Solve for x
   x = 1,369,530.20/1,395.49
6. Step 6: Final answer
   x = 981.40