Finding the Fourth Proportional to 978.86, 1,350.78 and 536.78

Step by Step Solution

1. Step 1: Write the proportion equation
   978.86 : 1,350.78 = 536.78 : x
2. Step 2: Convert to fraction form
   978.86/1,350.78 = 536.78/x
3. Step 3: Cross multiply
   978.86x = 1,350.78 × 536.78
4. Step 4: Simplify right side
   978.86x = 725,071.69
5. Step 5: Solve for x
   x = 725,071.69/978.86
6. Step 6: Final answer
   x = 740.73