Finding the Fourth Proportional to 103,172.72, 142,317.88 and 64,871.57

Step by Step Solution

1. Step 1: Write the proportion equation
   103,172.72 : 142,317.88 = 64,871.57 : x
2. Step 2: Convert to fraction form
   103,172.72/142,317.88 = 64,871.57/x
3. Step 3: Cross multiply
   103,172.72x = 142,317.88 × 64,871.57
4. Step 4: Simplify right side
   103,172.72x = 9,232,384,508.29
5. Step 5: Solve for x
   x = 9,232,384,508.29/103,172.72
6. Step 6: Final answer
   x = 89,484.75