Finding the Fourth Proportional to 1,018.17, 1,406.16 and 981.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.17 : 1,406.16 = 981.72 : x
2. Step 2: Convert to fraction form
   1,018.17/1,406.16 = 981.72/x
3. Step 3: Cross multiply
   1,018.17x = 1,406.16 × 981.72
4. Step 4: Simplify right side
   1,018.17x = 1,380,455.40
5. Step 5: Solve for x
   x = 1,380,455.40/1,018.17
6. Step 6: Final answer
   x = 1,355.82