Finding the Fourth Proportional to 1,579.21, 2,178.82 and 1,020.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,579.21 : 2,178.82 = 1,020.31 : x
2. Step 2: Convert to fraction form
   1,579.21/2,178.82 = 1,020.31/x
3. Step 3: Cross multiply
   1,579.21x = 2,178.82 × 1,020.31
4. Step 4: Simplify right side
   1,579.21x = 2,223,071.83
5. Step 5: Solve for x
   x = 2,223,071.83/1,579.21
6. Step 6: Final answer
   x = 1,407.71