Finding the Fourth Proportional to 1,989.54, 2,745.06 and 1,290.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,989.54 : 2,745.06 = 1,290.50 : x
2. Step 2: Convert to fraction form
   1,989.54/2,745.06 = 1,290.50/x
3. Step 3: Cross multiply
   1,989.54x = 2,745.06 × 1,290.50
4. Step 4: Simplify right side
   1,989.54x = 3,542,499.93
5. Step 5: Solve for x
   x = 3,542,499.93/1,989.54
6. Step 6: Final answer
   x = 1,780.56