Finding the Fourth Proportional to 2,653.60, 3,978.80 and 1,357.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,653.60 : 3,978.80 = 1,357.60 : x
2. Step 2: Convert to fraction form
   2,653.60/3,978.80 = 1,357.60/x
3. Step 3: Cross multiply
   2,653.60x = 3,978.80 × 1,357.60
4. Step 4: Simplify right side
   2,653.60x = 5,401,618.88
5. Step 5: Solve for x
   x = 5,401,618.88/2,653.60
6. Step 6: Final answer
   x = 2,035.58