Finding the Fourth Proportional to 2,987.72, 4,481.81 and 907.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,987.72 : 4,481.81 = 907.89 : x
2. Step 2: Convert to fraction form
   2,987.72/4,481.81 = 907.89/x
3. Step 3: Cross multiply
   2,987.72x = 4,481.81 × 907.89
4. Step 4: Simplify right side
   2,987.72x = 4,068,990.48
5. Step 5: Solve for x
   x = 4,068,990.48/2,987.72
6. Step 6: Final answer
   x = 1,361.90