Finding the Fourth Proportional to 1,426.06, 2,139.39 and 810.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,426.06 : 2,139.39 = 810.05 : x
2. Step 2: Convert to fraction form
   1,426.06/2,139.39 = 810.05/x
3. Step 3: Cross multiply
   1,426.06x = 2,139.39 × 810.05
4. Step 4: Simplify right side
   1,426.06x = 1,733,012.87
5. Step 5: Solve for x
   x = 1,733,012.87/1,426.06
6. Step 6: Final answer
   x = 1,215.25