Finding the Fourth Proportional to 12,390.53, 17,099.95 and 7,086.37

Step by Step Solution

1. Step 1: Write the proportion equation
   12,390.53 : 17,099.95 = 7,086.37 : x
2. Step 2: Convert to fraction form
   12,390.53/17,099.95 = 7,086.37/x
3. Step 3: Cross multiply
   12,390.53x = 17,099.95 × 7,086.37
4. Step 4: Simplify right side
   12,390.53x = 121,176,538.79
5. Step 5: Solve for x
   x = 121,176,538.79/12,390.53
6. Step 6: Final answer
   x = 9,779.77