Finding the Fourth Proportional to 10,980.28, 16,461.78 and 7,858

Step by Step Solution

1. Step 1: Write the proportion equation
   10,980.28 : 16,461.78 = 7,858 : x
2. Step 2: Convert to fraction form
   10,980.28/16,461.78 = 7,858/x
3. Step 3: Cross multiply
   10,980.28x = 16,461.78 × 7,858
4. Step 4: Simplify right side
   10,980.28x = 129,356,667.24
5. Step 5: Solve for x
   x = 129,356,667.24/10,980.28
6. Step 6: Final answer
   x = 11,780.82