Finding the Fourth Proportional to 72,142.88, 99,445.20 and 70,743.20

Step by Step Solution

1. Step 1: Write the proportion equation
   72,142.88 : 99,445.20 = 70,743.20 : x
2. Step 2: Convert to fraction form
   72,142.88/99,445.20 = 70,743.20/x
3. Step 3: Cross multiply
   72,142.88x = 99,445.20 × 70,743.20
4. Step 4: Simplify right side
   72,142.88x = 7,035,071,672.64
5. Step 5: Solve for x
   x = 7,035,071,672.64/72,142.88
6. Step 6: Final answer
   x = 97,515.81