Finding the Fourth Proportional to 1,397.72, 2,096.89 and 520.49

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.72 : 2,096.89 = 520.49 : x
2. Step 2: Convert to fraction form
   1,397.72/2,096.89 = 520.49/x
3. Step 3: Cross multiply
   1,397.72x = 2,096.89 × 520.49
4. Step 4: Simplify right side
   1,397.72x = 1,091,414.22
5. Step 5: Solve for x
   x = 1,091,414.22/1,397.72
6. Step 6: Final answer
   x = 780.85