Finding the Fourth Proportional to 28,181.51, 42,271.98 and 7,121.12

Step by Step Solution

1. Step 1: Write the proportion equation
   28,181.51 : 42,271.98 = 7,121.12 : x
2. Step 2: Convert to fraction form
   28,181.51/42,271.98 = 7,121.12/x
3. Step 3: Cross multiply
   28,181.51x = 42,271.98 × 7,121.12
4. Step 4: Simplify right side
   28,181.51x = 301,023,841.93
5. Step 5: Solve for x
   x = 301,023,841.93/28,181.51
6. Step 6: Final answer
   x = 10,681.61