Finding the Fourth Proportional to 1,211.89, 1,672.41 and 687.93

Step by Step Solution

1. Step 1: Write the proportion equation
   1,211.89 : 1,672.41 = 687.93 : x
2. Step 2: Convert to fraction form
   1,211.89/1,672.41 = 687.93/x
3. Step 3: Cross multiply
   1,211.89x = 1,672.41 × 687.93
4. Step 4: Simplify right side
   1,211.89x = 1,150,492.65
5. Step 5: Solve for x
   x = 1,150,492.65/1,211.89
6. Step 6: Final answer
   x = 949.34