Finding the Fourth Proportional to 78,128.69, 117,198.50 and 38,675.21

Step by Step Solution

1. Step 1: Write the proportion equation
   78,128.69 : 117,198.50 = 38,675.21 : x
2. Step 2: Convert to fraction form
   78,128.69/117,198.50 = 38,675.21/x
3. Step 3: Cross multiply
   78,128.69x = 117,198.50 × 38,675.21
4. Step 4: Simplify right side
   78,128.69x = 4,532,675,819.82
5. Step 5: Solve for x
   x = 4,532,675,819.82/78,128.69
6. Step 6: Final answer
   x = 58,015.51