Finding the Fourth Proportional to 5,114.78, 7,059.58 and 2,991.30

Step by Step Solution

1. Step 1: Write the proportion equation
   5,114.78 : 7,059.58 = 2,991.30 : x
2. Step 2: Convert to fraction form
   5,114.78/7,059.58 = 2,991.30/x
3. Step 3: Cross multiply
   5,114.78x = 7,059.58 × 2,991.30
4. Step 4: Simplify right side
   5,114.78x = 21,117,321.65
5. Step 5: Solve for x
   x = 21,117,321.65/5,114.78
6. Step 6: Final answer
   x = 4,128.69