Finding the Fourth Proportional to 1,425.18, 2,139.27 and 810.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,425.18 : 2,139.27 = 810.09 : x
2. Step 2: Convert to fraction form
   1,425.18/2,139.27 = 810.09/x
3. Step 3: Cross multiply
   1,425.18x = 2,139.27 × 810.09
4. Step 4: Simplify right side
   1,425.18x = 1,733,001.23
5. Step 5: Solve for x
   x = 1,733,001.23/1,425.18
6. Step 6: Final answer
   x = 1,215.99