Finding the Fourth Proportional to 7,980.05, 11,888.18 and 7,620.21

Step by Step Solution

1. Step 1: Write the proportion equation
   7,980.05 : 11,888.18 = 7,620.21 : x
2. Step 2: Convert to fraction form
   7,980.05/11,888.18 = 7,620.21/x
3. Step 3: Cross multiply
   7,980.05x = 11,888.18 × 7,620.21
4. Step 4: Simplify right side
   7,980.05x = 90,590,390.02
5. Step 5: Solve for x
   x = 90,590,390.02/7,980.05
6. Step 6: Final answer
   x = 11,352.12