Finding the Fourth Proportional to 13,070.31, 18,039.63 and 7,764.09

Step by Step Solution

1. Step 1: Write the proportion equation
   13,070.31 : 18,039.63 = 7,764.09 : x
2. Step 2: Convert to fraction form
   13,070.31/18,039.63 = 7,764.09/x
3. Step 3: Cross multiply
   13,070.31x = 18,039.63 × 7,764.09
4. Step 4: Simplify right side
   13,070.31x = 140,061,310.89
5. Step 5: Solve for x
   x = 140,061,310.89/13,070.31
6. Step 6: Final answer
   x = 10,715.99