Finding the Fourth Proportional to 139,579.53, 209,455.40 and 64,685.72

Step by Step Solution

1. Step 1: Write the proportion equation
   139,579.53 : 209,455.40 = 64,685.72 : x
2. Step 2: Convert to fraction form
   139,579.53/209,455.40 = 64,685.72/x
3. Step 3: Cross multiply
   139,579.53x = 209,455.40 × 64,685.72
4. Step 4: Simplify right side
   139,579.53x = 13,548,773,356.89
5. Step 5: Solve for x
   x = 13,548,773,356.89/139,579.53
6. Step 6: Final answer
   x = 97,068.48