Finding the Fourth Proportional to 1,425.15, 2,138.27 and 1,420.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,425.15 : 2,138.27 = 1,420.83 : x
2. Step 2: Convert to fraction form
   1,425.15/2,138.27 = 1,420.83/x
3. Step 3: Cross multiply
   1,425.15x = 2,138.27 × 1,420.83
4. Step 4: Simplify right side
   1,425.15x = 3,038,111.06
5. Step 5: Solve for x
   x = 3,038,111.06/1,425.15
6. Step 6: Final answer
   x = 2,131.78