Finding the Fourth Proportional to 1,023.78, 1,412.42 and 630.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,023.78 : 1,412.42 = 630.12 : x
2. Step 2: Convert to fraction form
   1,023.78/1,412.42 = 630.12/x
3. Step 3: Cross multiply
   1,023.78x = 1,412.42 × 630.12
4. Step 4: Simplify right side
   1,023.78x = 889,999.78
5. Step 5: Solve for x
   x = 889,999.78/1,023.78
6. Step 6: Final answer
   x = 869.32