Finding the Fourth Proportional to 56,578.68, 78,078.42 and 31,428

Step by Step Solution

1. Step 1: Write the proportion equation
   56,578.68 : 78,078.42 = 31,428 : x
2. Step 2: Convert to fraction form
   56,578.68/78,078.42 = 31,428/x
3. Step 3: Cross multiply
   56,578.68x = 78,078.42 × 31,428
4. Step 4: Simplify right side
   56,578.68x = 2,453,848,583.76
5. Step 5: Solve for x
   x = 2,453,848,583.76/56,578.68
6. Step 6: Final answer
   x = 43,370.55