Finding the Fourth Proportional to 7,165.22, 9,888.59 and 3,978.71

Step by Step Solution

1. Step 1: Write the proportion equation
   7,165.22 : 9,888.59 = 3,978.71 : x
2. Step 2: Convert to fraction form
   7,165.22/9,888.59 = 3,978.71/x
3. Step 3: Cross multiply
   7,165.22x = 9,888.59 × 3,978.71
4. Step 4: Simplify right side
   7,165.22x = 39,343,866.59
5. Step 5: Solve for x
   x = 39,343,866.59/7,165.22
6. Step 6: Final answer
   x = 5,490.95