Finding the Fourth Proportional to 2,106.88, 2,907.57 and 1,223.17

Step by Step Solution

1. Step 1: Write the proportion equation
   2,106.88 : 2,907.57 = 1,223.17 : x
2. Step 2: Convert to fraction form
   2,106.88/2,907.57 = 1,223.17/x
3. Step 3: Cross multiply
   2,106.88x = 2,907.57 × 1,223.17
4. Step 4: Simplify right side
   2,106.88x = 3,556,452.40
5. Step 5: Solve for x
   x = 3,556,452.40/2,106.88
6. Step 6: Final answer
   x = 1,688.02