Finding the Fourth Proportional to 12,086.96, 18,128.40 and 4,690.28

Step by Step Solution

1. Step 1: Write the proportion equation
   12,086.96 : 18,128.40 = 4,690.28 : x
2. Step 2: Convert to fraction form
   12,086.96/18,128.40 = 4,690.28/x
3. Step 3: Cross multiply
   12,086.96x = 18,128.40 × 4,690.28
4. Step 4: Simplify right side
   12,086.96x = 85,027,271.95
5. Step 5: Solve for x
   x = 85,027,271.95/12,086.96
6. Step 6: Final answer
   x = 7,034.63