Finding the Fourth Proportional to 1,139.96, 1,698.15 and 1,105.53

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.96 : 1,698.15 = 1,105.53 : x
2. Step 2: Convert to fraction form
   1,139.96/1,698.15 = 1,105.53/x
3. Step 3: Cross multiply
   1,139.96x = 1,698.15 × 1,105.53
4. Step 4: Simplify right side
   1,139.96x = 1,877,355.77
5. Step 5: Solve for x
   x = 1,877,355.77/1,139.96
6. Step 6: Final answer
   x = 1,646.87