Finding the Fourth Proportional to 78,142.56, 117,212.20 and 18,978.52

Step by Step Solution

1. Step 1: Write the proportion equation
   78,142.56 : 117,212.20 = 18,978.52 : x
2. Step 2: Convert to fraction form
   78,142.56/117,212.20 = 18,978.52/x
3. Step 3: Cross multiply
   78,142.56x = 117,212.20 × 18,978.52
4. Step 4: Simplify right side
   78,142.56x = 2,224,514,081.94
5. Step 5: Solve for x
   x = 2,224,514,081.94/78,142.56
6. Step 6: Final answer
   x = 28,467.38