Finding the Fourth Proportional to 1,396.89, 1,927.80 and 899.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,396.89 : 1,927.80 = 899.55 : x
2. Step 2: Convert to fraction form
   1,396.89/1,927.80 = 899.55/x
3. Step 3: Cross multiply
   1,396.89x = 1,927.80 × 899.55
4. Step 4: Simplify right side
   1,396.89x = 1,734,152.49
5. Step 5: Solve for x
   x = 1,734,152.49/1,396.89
6. Step 6: Final answer
   x = 1,241.44