Finding the Fourth Proportional to 1,395.95, 1,921.57 and 1,206.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,395.95 : 1,921.57 = 1,206.81 : x
2. Step 2: Convert to fraction form
   1,395.95/1,921.57 = 1,206.81/x
3. Step 3: Cross multiply
   1,395.95x = 1,921.57 × 1,206.81
4. Step 4: Simplify right side
   1,395.95x = 2,318,969.89
5. Step 5: Solve for x
   x = 2,318,969.89/1,395.95
6. Step 6: Final answer
   x = 1,661.21