Finding the Fourth Proportional to 256,139.18, 353,457.69 and 142,969.22

Step by Step Solution

1. Step 1: Write the proportion equation
   256,139.18 : 353,457.69 = 142,969.22 : x
2. Step 2: Convert to fraction form
   256,139.18/353,457.69 = 142,969.22/x
3. Step 3: Cross multiply
   256,139.18x = 353,457.69 × 142,969.22
4. Step 4: Simplify right side
   256,139.18x = 50,533,570,242.30
5. Step 5: Solve for x
   x = 50,533,570,242.30/256,139.18
6. Step 6: Final answer
   x = 197,289.50