Finding the Fourth Proportional to 12,978.23, 17,909.71 and 7,312.88

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978.23 : 17,909.71 = 7,312.88 : x
2. Step 2: Convert to fraction form
   12,978.23/17,909.71 = 7,312.88/x
3. Step 3: Cross multiply
   12,978.23x = 17,909.71 × 7,312.88
4. Step 4: Simplify right side
   12,978.23x = 130,971,586.56
5. Step 5: Solve for x
   x = 130,971,586.56/12,978.23
6. Step 6: Final answer
   x = 10,091.64