Finding the Fourth Proportional to 2,218.34, 3,061.20 and 1,223.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,218.34 : 3,061.20 = 1,223.72 : x
2. Step 2: Convert to fraction form
   2,218.34/3,061.20 = 1,223.72/x
3. Step 3: Cross multiply
   2,218.34x = 3,061.20 × 1,223.72
4. Step 4: Simplify right side
   2,218.34x = 3,746,051.66
5. Step 5: Solve for x
   x = 3,746,051.66/2,218.34
6. Step 6: Final answer
   x = 1,688.67