Finding the Fourth Proportional to 1,978.88, 2,727.90 and 1,661.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.88 : 2,727.90 = 1,661.76 : x
2. Step 2: Convert to fraction form
   1,978.88/2,727.90 = 1,661.76/x
3. Step 3: Cross multiply
   1,978.88x = 2,727.90 × 1,661.76
4. Step 4: Simplify right side
   1,978.88x = 4,533,115.10
5. Step 5: Solve for x
   x = 4,533,115.10/1,978.88
6. Step 6: Final answer
   x = 2,290.75