Finding the Fourth Proportional to 1,013.59, 1,398.73 and 571.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,013.59 : 1,398.73 = 571.50 : x
2. Step 2: Convert to fraction form
   1,013.59/1,398.73 = 571.50/x
3. Step 3: Cross multiply
   1,013.59x = 1,398.73 × 571.50
4. Step 4: Simplify right side
   1,013.59x = 799,374.20
5. Step 5: Solve for x
   x = 799,374.20/1,013.59
6. Step 6: Final answer
   x = 788.66