Finding the Fourth Proportional to 2,428.56, 3,642.78 and 697.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,428.56 : 3,642.78 = 697.20 : x
2. Step 2: Convert to fraction form
   2,428.56/3,642.78 = 697.20/x
3. Step 3: Cross multiply
   2,428.56x = 3,642.78 × 697.20
4. Step 4: Simplify right side
   2,428.56x = 2,539,746.22
5. Step 5: Solve for x
   x = 2,539,746.22/2,428.56
6. Step 6: Final answer
   x = 1,045.78