Finding the Fourth Proportional to 1,428.84, 1,972.89 and 981.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.84 : 1,972.89 = 981.18 : x
2. Step 2: Convert to fraction form
   1,428.84/1,972.89 = 981.18/x
3. Step 3: Cross multiply
   1,428.84x = 1,972.89 × 981.18
4. Step 4: Simplify right side
   1,428.84x = 1,935,760.21
5. Step 5: Solve for x
   x = 1,935,760.21/1,428.84
6. Step 6: Final answer
   x = 1,354.78