Finding the Fourth Proportional to 1,227.55, 1,695.72 and 978.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,227.55 : 1,695.72 = 978.54 : x
2. Step 2: Convert to fraction form
   1,227.55/1,695.72 = 978.54/x
3. Step 3: Cross multiply
   1,227.55x = 1,695.72 × 978.54
4. Step 4: Simplify right side
   1,227.55x = 1,659,324.96
5. Step 5: Solve for x
   x = 1,659,324.96/1,227.55
6. Step 6: Final answer
   x = 1,351.74