Finding the Fourth Proportional to 78,072.18, 117,036.50 and 28,140.05

Step by Step Solution

1. Step 1: Write the proportion equation
   78,072.18 : 117,036.50 = 28,140.05 : x
2. Step 2: Convert to fraction form
   78,072.18/117,036.50 = 28,140.05/x
3. Step 3: Cross multiply
   78,072.18x = 117,036.50 × 28,140.05
4. Step 4: Simplify right side
   78,072.18x = 3,293,412,235.94
5. Step 5: Solve for x
   x = 3,293,412,235.94/78,072.18
6. Step 6: Final answer
   x = 42,184.20