Finding the Third Proportional to 121,518.56 and 287,119.69

Step by Step Solution

1. Step 1: Write the proportion equation
   121,518.56 : 287,119.69 = 287,119.69 : x
2. Step 2: Convert to fraction form
   121,518.56/287,119.69 = 287,119.69/x
3. Step 3: Cross multiply
   121,518.56x = 287,119.69 × 287,119.69
4. Step 4: Simplify right side
   121,518.56x = 82,437,714,950.10
5. Step 5: Solve for x
   x = 82,437,714,950.10/121,518.56
6. Step 6: Final answer
   x = 678,396.07