Finding the Fourth Proportional to 2,221.75, 3,066.29 and 1,290.25

Step by Step Solution

1. Step 1: Write the proportion equation
   2,221.75 : 3,066.29 = 1,290.25 : x
2. Step 2: Convert to fraction form
   2,221.75/3,066.29 = 1,290.25/x
3. Step 3: Cross multiply
   2,221.75x = 3,066.29 × 1,290.25
4. Step 4: Simplify right side
   2,221.75x = 3,956,280.67
5. Step 5: Solve for x
   x = 3,956,280.67/2,221.75
6. Step 6: Final answer
   x = 1,780.70