Finding the Fourth Proportional to 2,221.57, 3,066.06 and 1,290.07

Step by Step Solution

1. Step 1: Write the proportion equation
   2,221.57 : 3,066.06 = 1,290.07 : x
2. Step 2: Convert to fraction form
   2,221.57/3,066.06 = 1,290.07/x
3. Step 3: Cross multiply
   2,221.57x = 3,066.06 × 1,290.07
4. Step 4: Simplify right side
   2,221.57x = 3,955,432.02
5. Step 5: Solve for x
   x = 3,955,432.02/2,221.57
6. Step 6: Final answer
   x = 1,780.47