Finding the Fourth Proportional to 2,218.19, 3,061.12 and 1,223.45

Step by Step Solution

1. Step 1: Write the proportion equation
   2,218.19 : 3,061.12 = 1,223.45 : x
2. Step 2: Convert to fraction form
   2,218.19/3,061.12 = 1,223.45/x
3. Step 3: Cross multiply
   2,218.19x = 3,061.12 × 1,223.45
4. Step 4: Simplify right side
   2,218.19x = 3,745,131.86
5. Step 5: Solve for x
   x = 3,745,131.86/2,218.19
6. Step 6: Final answer
   x = 1,688.37