Finding the Fourth Proportional to 15,870.87, 21,902.00 and 9,157.89

Step by Step Solution

1. Step 1: Write the proportion equation
   15,870.87 : 21,902.00 = 9,157.89 : x
2. Step 2: Convert to fraction form
   15,870.87/21,902.00 = 9,157.89/x
3. Step 3: Cross multiply
   15,870.87x = 21,902.00 × 9,157.89
4. Step 4: Simplify right side
   15,870.87x = 200,576,143.12
5. Step 5: Solve for x
   x = 200,576,143.12/15,870.87
6. Step 6: Final answer
   x = 12,638.01