Finding the Fourth Proportional to 80,420.41, 120,507.60 and 42,985.81

Step by Step Solution

1. Step 1: Write the proportion equation
   80,420.41 : 120,507.60 = 42,985.81 : x
2. Step 2: Convert to fraction form
   80,420.41/120,507.60 = 42,985.81/x
3. Step 3: Cross multiply
   80,420.41x = 120,507.60 × 42,985.81
4. Step 4: Simplify right side
   80,420.41x = 5,180,116,189.34
5. Step 5: Solve for x
   x = 5,180,116,189.34/80,420.41
6. Step 6: Final answer
   x = 64,412.95