Finding the Fourth Proportional to 2,179.21, 3,007.35 and 1,222.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,179.21 : 3,007.35 = 1,222.15 : x
2. Step 2: Convert to fraction form
   2,179.21/3,007.35 = 1,222.15/x
3. Step 3: Cross multiply
   2,179.21x = 3,007.35 × 1,222.15
4. Step 4: Simplify right side
   2,179.21x = 3,675,432.80
5. Step 5: Solve for x
   x = 3,675,432.80/2,179.21
6. Step 6: Final answer
   x = 1,686.59