Finding the Fourth Proportional to 981.32, 1,355.52 and 720.72

Step by Step Solution

1. Step 1: Write the proportion equation
   981.32 : 1,355.52 = 720.72 : x
2. Step 2: Convert to fraction form
   981.32/1,355.52 = 720.72/x
3. Step 3: Cross multiply
   981.32x = 1,355.52 × 720.72
4. Step 4: Simplify right side
   981.32x = 976,950.37
5. Step 5: Solve for x
   x = 976,950.37/981.32
6. Step 6: Final answer
   x = 995.55