Finding the Fourth Proportional to 28,457.70, 42,692.89 and 8,738.25

Step by Step Solution

1. Step 1: Write the proportion equation
   28,457.70 : 42,692.89 = 8,738.25 : x
2. Step 2: Convert to fraction form
   28,457.70/42,692.89 = 8,738.25/x
3. Step 3: Cross multiply
   28,457.70x = 42,692.89 × 8,738.25
4. Step 4: Simplify right side
   28,457.70x = 373,061,146.04
5. Step 5: Solve for x
   x = 373,061,146.04/28,457.70
6. Step 6: Final answer
   x = 13,109.32