Finding the Fourth Proportional to 2,931.78, 4,397.50 and 851.74

Step by Step Solution

1. Step 1: Write the proportion equation
   2,931.78 : 4,397.50 = 851.74 : x
2. Step 2: Convert to fraction form
   2,931.78/4,397.50 = 851.74/x
3. Step 3: Cross multiply
   2,931.78x = 4,397.50 × 851.74
4. Step 4: Simplify right side
   2,931.78x = 3,745,513.53
5. Step 5: Solve for x
   x = 3,745,513.53/2,931.78
6. Step 6: Final answer
   x = 1,277.56