Finding the Fourth Proportional to 128,300.34, 192,430.30 and 42,910.55

Step by Step Solution

1. Step 1: Write the proportion equation
   128,300.34 : 192,430.30 = 42,910.55 : x
2. Step 2: Convert to fraction form
   128,300.34/192,430.30 = 42,910.55/x
3. Step 3: Cross multiply
   128,300.34x = 192,430.30 × 42,910.55
4. Step 4: Simplify right side
   128,300.34x = 8,257,290,009.67
5. Step 5: Solve for x
   x = 8,257,290,009.67/128,300.34
6. Step 6: Final answer
   x = 64,359.07