Finding the Fourth Proportional to 7,870.40, 10,862.34 and 5,978.88

Step by Step Solution

1. Step 1: Write the proportion equation
   7,870.40 : 10,862.34 = 5,978.88 : x
2. Step 2: Convert to fraction form
   7,870.40/10,862.34 = 5,978.88/x
3. Step 3: Cross multiply
   7,870.40x = 10,862.34 × 5,978.88
4. Step 4: Simplify right side
   7,870.40x = 64,944,627.38
5. Step 5: Solve for x
   x = 64,944,627.38/7,870.40
6. Step 6: Final answer
   x = 8,251.76