Finding the Fourth Proportional to 13,978.47, 19,290.18 and 7,929.87

Step by Step Solution

1. Step 1: Write the proportion equation
   13,978.47 : 19,290.18 = 7,929.87 : x
2. Step 2: Convert to fraction form
   13,978.47/19,290.18 = 7,929.87/x
3. Step 3: Cross multiply
   13,978.47x = 19,290.18 × 7,929.87
4. Step 4: Simplify right side
   13,978.47x = 152,968,619.68
5. Step 5: Solve for x
   x = 152,968,619.68/13,978.47
6. Step 6: Final answer
   x = 10,943.16