Finding the Fourth Proportional to 5,380.79, 7,423.35 and 3,111.71

Step by Step Solution

1. Step 1: Write the proportion equation
   5,380.79 : 7,423.35 = 3,111.71 : x
2. Step 2: Convert to fraction form
   5,380.79/7,423.35 = 3,111.71/x
3. Step 3: Cross multiply
   5,380.79x = 7,423.35 × 3,111.71
4. Step 4: Simplify right side
   5,380.79x = 23,099,312.43
5. Step 5: Solve for x
   x = 23,099,312.43/5,380.79
6. Step 6: Final answer
   x = 4,292.93