Finding the Fourth Proportional to 3,904.78, 5,388.50 and 2,311.51

Step by Step Solution

1. Step 1: Write the proportion equation
   3,904.78 : 5,388.50 = 2,311.51 : x
2. Step 2: Convert to fraction form
   3,904.78/5,388.50 = 2,311.51/x
3. Step 3: Cross multiply
   3,904.78x = 5,388.50 × 2,311.51
4. Step 4: Simplify right side
   3,904.78x = 12,455,566.81
5. Step 5: Solve for x
   x = 12,455,566.81/3,904.78
6. Step 6: Final answer
   x = 3,189.82