Finding the Fourth Proportional to 142,842.80, 214,309.47 and 85,978.98

Step by Step Solution

1. Step 1: Write the proportion equation
   142,842.80 : 214,309.47 = 85,978.98 : x
2. Step 2: Convert to fraction form
   142,842.80/214,309.47 = 85,978.98/x
3. Step 3: Cross multiply
   142,842.80x = 214,309.47 × 85,978.98
4. Step 4: Simplify right side
   142,842.80x = 18,426,109,634.94
5. Step 5: Solve for x
   x = 18,426,109,634.94/142,842.80
6. Step 6: Final answer
   x = 128,995.72