Finding the Fourth Proportional to 7,847.18, 10,820.40 and 7,665.74

Step by Step Solution

1. Step 1: Write the proportion equation
   7,847.18 : 10,820.40 = 7,665.74 : x
2. Step 2: Convert to fraction form
   7,847.18/10,820.40 = 7,665.74/x
3. Step 3: Cross multiply
   7,847.18x = 10,820.40 × 7,665.74
4. Step 4: Simplify right side
   7,847.18x = 82,946,373.10
5. Step 5: Solve for x
   x = 82,946,373.10/7,847.18
6. Step 6: Final answer
   x = 10,570.21