Finding the Fourth Proportional to 1,158.61, 1,738.59 and 428.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,158.61 : 1,738.59 = 428.24 : x
2. Step 2: Convert to fraction form
   1,158.61/1,738.59 = 428.24/x
3. Step 3: Cross multiply
   1,158.61x = 1,738.59 × 428.24
4. Step 4: Simplify right side
   1,158.61x = 744,533.78
5. Step 5: Solve for x
   x = 744,533.78/1,158.61
6. Step 6: Final answer
   x = 642.61