Finding the Fourth Proportional to 1,351.78, 1,865.32 and 997.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,351.78 : 1,865.32 = 997.89 : x
2. Step 2: Convert to fraction form
   1,351.78/1,865.32 = 997.89/x
3. Step 3: Cross multiply
   1,351.78x = 1,865.32 × 997.89
4. Step 4: Simplify right side
   1,351.78x = 1,861,381.68
5. Step 5: Solve for x
   x = 1,861,381.68/1,351.78
6. Step 6: Final answer
   x = 1,376.99