Finding the Fourth Proportional to 870.72, 1,201.59 and 477.78

Step by Step Solution

1. Step 1: Write the proportion equation
   870.72 : 1,201.59 = 477.78 : x
2. Step 2: Convert to fraction form
   870.72/1,201.59 = 477.78/x
3. Step 3: Cross multiply
   870.72x = 1,201.59 × 477.78
4. Step 4: Simplify right side
   870.72x = 574,095.67
5. Step 5: Solve for x
   x = 574,095.67/870.72
6. Step 6: Final answer
   x = 659.33