Finding the Fourth Proportional to 1,210.72, 1,671.78 and 986.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,210.72 : 1,671.78 = 986.69 : x
2. Step 2: Convert to fraction form
   1,210.72/1,671.78 = 986.69/x
3. Step 3: Cross multiply
   1,210.72x = 1,671.78 × 986.69
4. Step 4: Simplify right side
   1,210.72x = 1,649,528.61
5. Step 5: Solve for x
   x = 1,649,528.61/1,210.72
6. Step 6: Final answer
   x = 1,362.44