Finding the Fourth Proportional to 28,389.89, 42,588.96 and 8,665.89

Step by Step Solution

1. Step 1: Write the proportion equation
   28,389.89 : 42,588.96 = 8,665.89 : x
2. Step 2: Convert to fraction form
   28,389.89/42,588.96 = 8,665.89/x
3. Step 3: Cross multiply
   28,389.89x = 42,588.96 × 8,665.89
4. Step 4: Simplify right side
   28,389.89x = 369,071,050.37
5. Step 5: Solve for x
   x = 369,071,050.37/28,389.89
6. Step 6: Final answer
   x = 13,000.09