Finding the Fourth Proportional to 28,570.78, 42,883.86 and 13,790.08

Step by Step Solution

1. Step 1: Write the proportion equation
   28,570.78 : 42,883.86 = 13,790.08 : x
2. Step 2: Convert to fraction form
   28,570.78/42,883.86 = 13,790.08/x
3. Step 3: Cross multiply
   28,570.78x = 42,883.86 × 13,790.08
4. Step 4: Simplify right side
   28,570.78x = 591,371,645.69
5. Step 5: Solve for x
   x = 591,371,645.69/28,570.78
6. Step 6: Final answer
   x = 20,698.48