Finding the Fourth Proportional to 1,978.56, 2,967.76 and 517.68

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.56 : 2,967.76 = 517.68 : x
2. Step 2: Convert to fraction form
   1,978.56/2,967.76 = 517.68/x
3. Step 3: Cross multiply
   1,978.56x = 2,967.76 × 517.68
4. Step 4: Simplify right side
   1,978.56x = 1,536,362.74
5. Step 5: Solve for x
   x = 1,536,362.74/1,978.56
6. Step 6: Final answer
   x = 776.50