Finding the Fourth Proportional to 2,218.76, 3,061.70 and 1,223.79

Step by Step Solution

1. Step 1: Write the proportion equation
   2,218.76 : 3,061.70 = 1,223.79 : x
2. Step 2: Convert to fraction form
   2,218.76/3,061.70 = 1,223.79/x
3. Step 3: Cross multiply
   2,218.76x = 3,061.70 × 1,223.79
4. Step 4: Simplify right side
   2,218.76x = 3,746,871.72
5. Step 5: Solve for x
   x = 3,746,871.72/2,218.76
6. Step 6: Final answer
   x = 1,688.73