Finding the Fourth Proportional to 28,111.39, 42,167.27 and 8,390.13

Step by Step Solution

1. Step 1: Write the proportion equation
   28,111.39 : 42,167.27 = 8,390.13 : x
2. Step 2: Convert to fraction form
   28,111.39/42,167.27 = 8,390.13/x
3. Step 3: Cross multiply
   28,111.39x = 42,167.27 × 8,390.13
4. Step 4: Simplify right side
   28,111.39x = 353,788,877.05
5. Step 5: Solve for x
   x = 353,788,877.05/28,111.39
6. Step 6: Final answer
   x = 12,585.25