Finding the Fourth Proportional to 109,401.20, 163,986.60 and 42,815.60

Step by Step Solution

1. Step 1: Write the proportion equation
   109,401.20 : 163,986.60 = 42,815.60 : x
2. Step 2: Convert to fraction form
   109,401.20/163,986.60 = 42,815.60/x
3. Step 3: Cross multiply
   109,401.20x = 163,986.60 × 42,815.60
4. Step 4: Simplify right side
   109,401.20x = 7,021,184,670.96
5. Step 5: Solve for x
   x = 7,021,184,670.96/109,401.20
6. Step 6: Final answer
   x = 64,178.31