Finding the Fourth Proportional to 1,158.53, 1,737.72 and 428.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,158.53 : 1,737.72 = 428.06 : x
2. Step 2: Convert to fraction form
   1,158.53/1,737.72 = 428.06/x
3. Step 3: Cross multiply
   1,158.53x = 1,737.72 × 428.06
4. Step 4: Simplify right side
   1,158.53x = 743,839.73
5. Step 5: Solve for x
   x = 743,839.73/1,158.53
6. Step 6: Final answer
   x = 642.06