Finding the Fourth Proportional to 1,405.89, 1,939.35 and 986.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.89 : 1,939.35 = 986.07 : x
2. Step 2: Convert to fraction form
   1,405.89/1,939.35 = 986.07/x
3. Step 3: Cross multiply
   1,405.89x = 1,939.35 × 986.07
4. Step 4: Simplify right side
   1,405.89x = 1,912,334.85
5. Step 5: Solve for x
   x = 1,912,334.85/1,405.89
6. Step 6: Final answer
   x = 1,360.23