Finding the Fourth Proportional to 1,428.91, 1,972.55 and 1,038.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.91 : 1,972.55 = 1,038.89 : x
2. Step 2: Convert to fraction form
   1,428.91/1,972.55 = 1,038.89/x
3. Step 3: Cross multiply
   1,428.91x = 1,972.55 × 1,038.89
4. Step 4: Simplify right side
   1,428.91x = 2,049,257.28
5. Step 5: Solve for x
   x = 2,049,257.28/1,428.91
6. Step 6: Final answer
   x = 1,434.15