Finding the Fourth Proportional to 1,605.55, 2,215.71 and 906.97

Step by Step Solution

1. Step 1: Write the proportion equation
   1,605.55 : 2,215.71 = 906.97 : x
2. Step 2: Convert to fraction form
   1,605.55/2,215.71 = 906.97/x
3. Step 3: Cross multiply
   1,605.55x = 2,215.71 × 906.97
4. Step 4: Simplify right side
   1,605.55x = 2,009,566.89
5. Step 5: Solve for x
   x = 2,009,566.89/1,605.55
6. Step 6: Final answer
   x = 1,251.64