Finding the Fourth Proportional to 1,020.34, 1,408.23 and 578.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,020.34 : 1,408.23 = 578.50 : x
2. Step 2: Convert to fraction form
   1,020.34/1,408.23 = 578.50/x
3. Step 3: Cross multiply
   1,020.34x = 1,408.23 × 578.50
4. Step 4: Simplify right side
   1,020.34x = 814,661.06
5. Step 5: Solve for x
   x = 814,661.06/1,020.34
6. Step 6: Final answer
   x = 798.42