Finding the Fourth Proportional to 1,353.80, 1,869.11 and 1,105.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,353.80 : 1,869.11 = 1,105.72 : x
2. Step 2: Convert to fraction form
   1,353.80/1,869.11 = 1,105.72/x
3. Step 3: Cross multiply
   1,353.80x = 1,869.11 × 1,105.72
4. Step 4: Simplify right side
   1,353.80x = 2,066,705.73
5. Step 5: Solve for x
   x = 2,066,705.73/1,353.80
6. Step 6: Final answer
   x = 1,526.60