Finding the Fourth Proportional to 1,968.74, 2,715.89 and 1,223.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,968.74 : 2,715.89 = 1,223.55 : x
2. Step 2: Convert to fraction form
   1,968.74/2,715.89 = 1,223.55/x
3. Step 3: Cross multiply
   1,968.74x = 2,715.89 × 1,223.55
4. Step 4: Simplify right side
   1,968.74x = 3,323,021.09
5. Step 5: Solve for x
   x = 3,323,021.09/1,968.74
6. Step 6: Final answer
   x = 1,687.90