Finding the Fourth Proportional to 12,980.18, 17,919.54 and 10,399.86

Step by Step Solution

1. Step 1: Write the proportion equation
   12,980.18 : 17,919.54 = 10,399.86 : x
2. Step 2: Convert to fraction form
   12,980.18/17,919.54 = 10,399.86/x
3. Step 3: Cross multiply
   12,980.18x = 17,919.54 × 10,399.86
4. Step 4: Simplify right side
   12,980.18x = 186,360,707.26
5. Step 5: Solve for x
   x = 186,360,707.26/12,980.18
6. Step 6: Final answer
   x = 14,357.33