Finding the Fourth Proportional to 78,240.64, 107,971.68 and 42,431.52

Step by Step Solution

1. Step 1: Write the proportion equation
   78,240.64 : 107,971.68 = 42,431.52 : x
2. Step 2: Convert to fraction form
   78,240.64/107,971.68 = 42,431.52/x
3. Step 3: Cross multiply
   78,240.64x = 107,971.68 × 42,431.52
4. Step 4: Simplify right side
   78,240.64x = 4,581,402,499.35
5. Step 5: Solve for x
   x = 4,581,402,499.35/78,240.64
6. Step 6: Final answer
   x = 58,555.28