Finding the Fourth Proportional to 10,128.55, 15,194.45 and 4,285.21

Step by Step Solution

1. Step 1: Write the proportion equation
   10,128.55 : 15,194.45 = 4,285.21 : x
2. Step 2: Convert to fraction form
   10,128.55/15,194.45 = 4,285.21/x
3. Step 3: Cross multiply
   10,128.55x = 15,194.45 × 4,285.21
4. Step 4: Simplify right side
   10,128.55x = 65,111,453.89
5. Step 5: Solve for x
   x = 65,111,453.89/10,128.55
6. Step 6: Final answer
   x = 6,428.50