Finding the Fourth Proportional to 80,303.91, 120,462.69 and 21,139.75

Step by Step Solution

1. Step 1: Write the proportion equation
   80,303.91 : 120,462.69 = 21,139.75 : x
2. Step 2: Convert to fraction form
   80,303.91/120,462.69 = 21,139.75/x
3. Step 3: Cross multiply
   80,303.91x = 120,462.69 × 21,139.75
4. Step 4: Simplify right side
   80,303.91x = 2,546,550,872.58
5. Step 5: Solve for x
   x = 2,546,550,872.58/80,303.91
6. Step 6: Final answer
   x = 31,711.42