Finding the Fourth Proportional to 2,073.76, 3,111.20 and 978.88

Step by Step Solution

1. Step 1: Write the proportion equation
   2,073.76 : 3,111.20 = 978.88 : x
2. Step 2: Convert to fraction form
   2,073.76/3,111.20 = 978.88/x
3. Step 3: Cross multiply
   2,073.76x = 3,111.20 × 978.88
4. Step 4: Simplify right side
   2,073.76x = 3,045,491.46
5. Step 5: Solve for x
   x = 3,045,491.46/2,073.76
6. Step 6: Final answer
   x = 1,468.58