Finding the Fourth Proportional to 12,978.50, 17,910.35 and 7,389.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978.50 : 17,910.35 = 7,389.50 : x
2. Step 2: Convert to fraction form
   12,978.50/17,910.35 = 7,389.50/x
3. Step 3: Cross multiply
   12,978.50x = 17,910.35 × 7,389.50
4. Step 4: Simplify right side
   12,978.50x = 132,348,531.33
5. Step 5: Solve for x
   x = 132,348,531.33/12,978.50
6. Step 6: Final answer
   x = 10,197.52