Finding the Fourth Proportional to 1,015.56, 1,521.65 and 721.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,015.56 : 1,521.65 = 721.59 : x
2. Step 2: Convert to fraction form
   1,015.56/1,521.65 = 721.59/x
3. Step 3: Cross multiply
   1,015.56x = 1,521.65 × 721.59
4. Step 4: Simplify right side
   1,015.56x = 1,098,003.82
5. Step 5: Solve for x
   x = 1,098,003.82/1,015.56
6. Step 6: Final answer
   x = 1,081.18