Finding the Fourth Proportional to 3,905.82, 5,377.86 and 3,689.28

Step by Step Solution

1. Step 1: Write the proportion equation
   3,905.82 : 5,377.86 = 3,689.28 : x
2. Step 2: Convert to fraction form
   3,905.82/5,377.86 = 3,689.28/x
3. Step 3: Cross multiply
   3,905.82x = 5,377.86 × 3,689.28
4. Step 4: Simplify right side
   3,905.82x = 19,840,431.34
5. Step 5: Solve for x
   x = 19,840,431.34/3,905.82
6. Step 6: Final answer
   x = 5,079.71