Finding the Fourth Proportional to 1,021.76, 1,409.82 and 579.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,021.76 : 1,409.82 = 579.59 : x
2. Step 2: Convert to fraction form
   1,021.76/1,409.82 = 579.59/x
3. Step 3: Cross multiply
   1,021.76x = 1,409.82 × 579.59
4. Step 4: Simplify right side
   1,021.76x = 817,116.90
5. Step 5: Solve for x
   x = 817,116.90/1,021.76
6. Step 6: Final answer
   x = 799.71