Finding the Fourth Proportional to 139,804.36, 209,655.50 and 51,031.60

Step by Step Solution

1. Step 1: Write the proportion equation
   139,804.36 : 209,655.50 = 51,031.60 : x
2. Step 2: Convert to fraction form
   139,804.36/209,655.50 = 51,031.60/x
3. Step 3: Cross multiply
   139,804.36x = 209,655.50 × 51,031.60
4. Step 4: Simplify right side
   139,804.36x = 10,699,054,834.50
5. Step 5: Solve for x
   x = 10,699,054,834.50/139,804.36
6. Step 6: Final answer
   x = 76,528.77