Finding the Fourth Proportional to 51,079.38, 76,618.79 and 13,128.62

Step by Step Solution

1. Step 1: Write the proportion equation
   51,079.38 : 76,618.79 = 13,128.62 : x
2. Step 2: Convert to fraction form
   51,079.38/76,618.79 = 13,128.62/x
3. Step 3: Cross multiply
   51,079.38x = 76,618.79 × 13,128.62
4. Step 4: Simplify right side
   51,079.38x = 1,005,898,978.77
5. Step 5: Solve for x
   x = 1,005,898,978.77/51,079.38
6. Step 6: Final answer
   x = 19,692.86