Finding the Fourth Proportional to 1,210.89, 1,671.05 and 686.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,210.89 : 1,671.05 = 686.94 : x
2. Step 2: Convert to fraction form
   1,210.89/1,671.05 = 686.94/x
3. Step 3: Cross multiply
   1,210.89x = 1,671.05 × 686.94
4. Step 4: Simplify right side
   1,210.89x = 1,147,911.09
5. Step 5: Solve for x
   x = 1,147,911.09/1,210.89
6. Step 6: Final answer
   x = 947.99