Finding the Fourth Proportional to 11,457.31, 17,176.16 and 5,215.09

Step by Step Solution

1. Step 1: Write the proportion equation
   11,457.31 : 17,176.16 = 5,215.09 : x
2. Step 2: Convert to fraction form
   11,457.31/17,176.16 = 5,215.09/x
3. Step 3: Cross multiply
   11,457.31x = 17,176.16 × 5,215.09
4. Step 4: Simplify right side
   11,457.31x = 89,575,254.76
5. Step 5: Solve for x
   x = 89,575,254.76/11,457.31
6. Step 6: Final answer
   x = 7,818.18