Finding the Fourth Proportional to 978.78, 1,350.78 and 536.69

Step by Step Solution

1. Step 1: Write the proportion equation
   978.78 : 1,350.78 = 536.69 : x
2. Step 2: Convert to fraction form
   978.78/1,350.78 = 536.69/x
3. Step 3: Cross multiply
   978.78x = 1,350.78 × 536.69
4. Step 4: Simplify right side
   978.78x = 724,951.48
5. Step 5: Solve for x
   x = 724,951.48/978.78
6. Step 6: Final answer
   x = 740.67