Finding the Fourth Proportional to 1,021.58, 1,409.72 and 579.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,021.58 : 1,409.72 = 579.56 : x
2. Step 2: Convert to fraction form
   1,021.58/1,409.72 = 579.56/x
3. Step 3: Cross multiply
   1,021.58x = 1,409.72 × 579.56
4. Step 4: Simplify right side
   1,021.58x = 817,017.32
5. Step 5: Solve for x
   x = 817,017.32/1,021.58
6. Step 6: Final answer
   x = 799.76