Finding the Fourth Proportional to 5,139.16, 7,091.70 and 2,870.47

Step by Step Solution

1. Step 1: Write the proportion equation
   5,139.16 : 7,091.70 = 2,870.47 : x
2. Step 2: Convert to fraction form
   5,139.16/7,091.70 = 2,870.47/x
3. Step 3: Cross multiply
   5,139.16x = 7,091.70 × 2,870.47
4. Step 4: Simplify right side
   5,139.16x = 20,356,512.10
5. Step 5: Solve for x
   x = 20,356,512.10/5,139.16
6. Step 6: Final answer
   x = 3,961.06