Finding the Fourth Proportional to 1,789.47, 2,681.78 and 1,328.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,789.47 : 2,681.78 = 1,328.99 : x
2. Step 2: Convert to fraction form
   1,789.47/2,681.78 = 1,328.99/x
3. Step 3: Cross multiply
   1,789.47x = 2,681.78 × 1,328.99
4. Step 4: Simplify right side
   1,789.47x = 3,564,038.75
5. Step 5: Solve for x
   x = 3,564,038.75/1,789.47
6. Step 6: Final answer
   x = 1,991.67