Finding the Fourth Proportional to 1,002.80, 1,383.72 and 609.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,002.80 : 1,383.72 = 609.86 : x
2. Step 2: Convert to fraction form
   1,002.80/1,383.72 = 609.86/x
3. Step 3: Cross multiply
   1,002.80x = 1,383.72 × 609.86
4. Step 4: Simplify right side
   1,002.80x = 843,875.48
5. Step 5: Solve for x
   x = 843,875.48/1,002.80
6. Step 6: Final answer
   x = 841.52