Finding the Fourth Proportional to 3,123.72, 4,684.76 and 931.86

Step by Step Solution

1. Step 1: Write the proportion equation
   3,123.72 : 4,684.76 = 931.86 : x
2. Step 2: Convert to fraction form
   3,123.72/4,684.76 = 931.86/x
3. Step 3: Cross multiply
   3,123.72x = 4,684.76 × 931.86
4. Step 4: Simplify right side
   3,123.72x = 4,365,540.45
5. Step 5: Solve for x
   x = 4,365,540.45/3,123.72
6. Step 6: Final answer
   x = 1,397.55