Finding the Fourth Proportional to 1,707.56, 2,564.60 and 978.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,707.56 : 2,564.60 = 978.56 : x
2. Step 2: Convert to fraction form
   1,707.56/2,564.60 = 978.56/x
3. Step 3: Cross multiply
   1,707.56x = 2,564.60 × 978.56
4. Step 4: Simplify right side
   1,707.56x = 2,509,614.98
5. Step 5: Solve for x
   x = 2,509,614.98/1,707.56
6. Step 6: Final answer
   x = 1,469.71