Finding the Fourth Proportional to 1,689.08, 2,323.20 and 1,356.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,689.08 : 2,323.20 = 1,356.78 : x
2. Step 2: Convert to fraction form
   1,689.08/2,323.20 = 1,356.78/x
3. Step 3: Cross multiply
   1,689.08x = 2,323.20 × 1,356.78
4. Step 4: Simplify right side
   1,689.08x = 3,152,071.30
5. Step 5: Solve for x
   x = 3,152,071.30/1,689.08
6. Step 6: Final answer
   x = 1,866.15