Finding the Fourth Proportional to 28,061.40, 42,091.80 and 8,340.12

Step by Step Solution

1. Step 1: Write the proportion equation
   28,061.40 : 42,091.80 = 8,340.12 : x
2. Step 2: Convert to fraction form
   28,061.40/42,091.80 = 8,340.12/x
3. Step 3: Cross multiply
   28,061.40x = 42,091.80 × 8,340.12
4. Step 4: Simplify right side
   28,061.40x = 351,050,663.02
5. Step 5: Solve for x
   x = 351,050,663.02/28,061.40
6. Step 6: Final answer
   x = 12,510.09