Finding the Fourth Proportional to 1,605.52, 2,215.43 and 906.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,605.52 : 2,215.43 = 906.89 : x
2. Step 2: Convert to fraction form
   1,605.52/2,215.43 = 906.89/x
3. Step 3: Cross multiply
   1,605.52x = 2,215.43 × 906.89
4. Step 4: Simplify right side
   1,605.52x = 2,009,151.31
5. Step 5: Solve for x
   x = 2,009,151.31/1,605.52
6. Step 6: Final answer
   x = 1,251.41