Finding the Fourth Proportional to 6,909.72, 10,362.90 and 1,978.20

Step by Step Solution

1. Step 1: Write the proportion equation
   6,909.72 : 10,362.90 = 1,978.20 : x
2. Step 2: Convert to fraction form
   6,909.72/10,362.90 = 1,978.20/x
3. Step 3: Cross multiply
   6,909.72x = 10,362.90 × 1,978.20
4. Step 4: Simplify right side
   6,909.72x = 20,499,888.78
5. Step 5: Solve for x
   x = 20,499,888.78/6,909.72
6. Step 6: Final answer
   x = 2,966.82