Finding the Fourth Proportional to 139,790.15, 209,605.27 and 64,871.76

Step by Step Solution

1. Step 1: Write the proportion equation
   139,790.15 : 209,605.27 = 64,871.76 : x
2. Step 2: Convert to fraction form
   139,790.15/209,605.27 = 64,871.76/x
3. Step 3: Cross multiply
   139,790.15x = 209,605.27 × 64,871.76
4. Step 4: Simplify right side
   139,790.15x = 13,597,462,770.18
5. Step 5: Solve for x
   x = 13,597,462,770.18/139,790.15
6. Step 6: Final answer
   x = 97,270.54