Finding the Fourth Proportional to 28,570.82, 42,883.86 and 13,790.15

Step by Step Solution

1. Step 1: Write the proportion equation
   28,570.82 : 42,883.86 = 13,790.15 : x
2. Step 2: Convert to fraction form
   28,570.82/42,883.86 = 13,790.15/x
3. Step 3: Cross multiply
   28,570.82x = 42,883.86 × 13,790.15
4. Step 4: Simplify right side
   28,570.82x = 591,374,647.56
5. Step 5: Solve for x
   x = 591,374,647.56/28,570.82
6. Step 6: Final answer
   x = 20,698.56