Finding the Fourth Proportional to 1,555.24, 2,143.74 and 1,428.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,555.24 : 2,143.74 = 1,428.10 : x
2. Step 2: Convert to fraction form
   1,555.24/2,143.74 = 1,428.10/x
3. Step 3: Cross multiply
   1,555.24x = 2,143.74 × 1,428.10
4. Step 4: Simplify right side
   1,555.24x = 3,061,475.09
5. Step 5: Solve for x
   x = 3,061,475.09/1,555.24
6. Step 6: Final answer
   x = 1,968.49