Finding the Fourth Proportional to 1,605.48, 2,215.59 and 906.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,605.48 : 2,215.59 = 906.87 : x
2. Step 2: Convert to fraction form
   1,605.48/2,215.59 = 906.87/x
3. Step 3: Cross multiply
   1,605.48x = 2,215.59 × 906.87
4. Step 4: Simplify right side
   1,605.48x = 2,009,252.10
5. Step 5: Solve for x
   x = 2,009,252.10/1,605.48
6. Step 6: Final answer
   x = 1,251.50