Finding the Fourth Proportional to 76,380, 105,405.12 and 42,846.72

Step by Step Solution

1. Step 1: Write the proportion equation
   76,380 : 105,405.12 = 42,846.72 : x
2. Step 2: Convert to fraction form
   76,380/105,405.12 = 42,846.72/x
3. Step 3: Cross multiply
   76,380x = 105,405.12 × 42,846.72
4. Step 4: Simplify right side
   76,380x = 4,516,263,663.21
5. Step 5: Solve for x
   x = 4,516,263,663.21/76,380
6. Step 6: Final answer
   x = 59,128.88