Finding the Fourth Proportional to 1,015.78, 1,401.77 and 573.68

Step by Step Solution

1. Step 1: Write the proportion equation
   1,015.78 : 1,401.77 = 573.68 : x
2. Step 2: Convert to fraction form
   1,015.78/1,401.77 = 573.68/x
3. Step 3: Cross multiply
   1,015.78x = 1,401.77 × 573.68
4. Step 4: Simplify right side
   1,015.78x = 804,157.54
5. Step 5: Solve for x
   x = 804,157.54/1,015.78
6. Step 6: Final answer
   x = 791.67