Finding the Fourth Proportional to 1,666.72, 2,499.84 and 800.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,666.72 : 2,499.84 = 800.80 : x
2. Step 2: Convert to fraction form
   1,666.72/2,499.84 = 800.80/x
3. Step 3: Cross multiply
   1,666.72x = 2,499.84 × 800.80
4. Step 4: Simplify right side
   1,666.72x = 2,001,871.87
5. Step 5: Solve for x
   x = 2,001,871.87/1,666.72
6. Step 6: Final answer
   x = 1,201.08