Finding the Fourth Proportional to 1,123.86, 1,686.06 and 630.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.86 : 1,686.06 = 630.78 : x
2. Step 2: Convert to fraction form
   1,123.86/1,686.06 = 630.78/x
3. Step 3: Cross multiply
   1,123.86x = 1,686.06 × 630.78
4. Step 4: Simplify right side
   1,123.86x = 1,063,532.93
5. Step 5: Solve for x
   x = 1,063,532.93/1,123.86
6. Step 6: Final answer
   x = 946.32