Finding the Fourth Proportional to 2,758.86, 4,139.01 and 810.99

Step by Step Solution

1. Step 1: Write the proportion equation
   2,758.86 : 4,139.01 = 810.99 : x
2. Step 2: Convert to fraction form
   2,758.86/4,139.01 = 810.99/x
3. Step 3: Cross multiply
   2,758.86x = 4,139.01 × 810.99
4. Step 4: Simplify right side
   2,758.86x = 3,356,695.72
5. Step 5: Solve for x
   x = 3,356,695.72/2,758.86
6. Step 6: Final answer
   x = 1,216.70