Finding the Fourth Proportional to 1,111.91, 1,669.28 and 906.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.91 : 1,669.28 = 906.87 : x
2. Step 2: Convert to fraction form
   1,111.91/1,669.28 = 906.87/x
3. Step 3: Cross multiply
   1,111.91x = 1,669.28 × 906.87
4. Step 4: Simplify right side
   1,111.91x = 1,513,821.68
5. Step 5: Solve for x
   x = 1,513,821.68/1,111.91
6. Step 6: Final answer
   x = 1,361.47