Finding the Fourth Proportional to 1,980.72, 2,968.80 and 809.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,980.72 : 2,968.80 = 809.88 : x
2. Step 2: Convert to fraction form
   1,980.72/2,968.80 = 809.88/x
3. Step 3: Cross multiply
   1,980.72x = 2,968.80 × 809.88
4. Step 4: Simplify right side
   1,980.72x = 2,404,371.74
5. Step 5: Solve for x
   x = 2,404,371.74/1,980.72
6. Step 6: Final answer
   x = 1,213.89