Finding the Fourth Proportional to 9,978.20, 13,768.98 and 5,786

Step by Step Solution

1. Step 1: Write the proportion equation
   9,978.20 : 13,768.98 = 5,786 : x
2. Step 2: Convert to fraction form
   9,978.20/13,768.98 = 5,786/x
3. Step 3: Cross multiply
   9,978.20x = 13,768.98 × 5,786
4. Step 4: Simplify right side
   9,978.20x = 79,667,318.28
5. Step 5: Solve for x
   x = 79,667,318.28/9,978.20
6. Step 6: Final answer
   x = 7,984.14