Finding the Fourth Proportional to 1,986.81, 2,978.07 and 1,293.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,986.81 : 2,978.07 = 1,293.99 : x
2. Step 2: Convert to fraction form
   1,986.81/2,978.07 = 1,293.99/x
3. Step 3: Cross multiply
   1,986.81x = 2,978.07 × 1,293.99
4. Step 4: Simplify right side
   1,986.81x = 3,853,592.80
5. Step 5: Solve for x
   x = 3,853,592.80/1,986.81
6. Step 6: Final answer
   x = 1,939.59