Finding the Fourth Proportional to 5,155.56, 7,671.33 and 5,138.28

Step by Step Solution

1. Step 1: Write the proportion equation
   5,155.56 : 7,671.33 = 5,138.28 : x
2. Step 2: Convert to fraction form
   5,155.56/7,671.33 = 5,138.28/x
3. Step 3: Cross multiply
   5,155.56x = 7,671.33 × 5,138.28
4. Step 4: Simplify right side
   5,155.56x = 39,417,441.51
5. Step 5: Solve for x
   x = 39,417,441.51/5,155.56
6. Step 6: Final answer
   x = 7,645.62