Finding the Fourth Proportional to 20,858.50, 28,784.73 and 12,475

Step by Step Solution

1. Step 1: Write the proportion equation
   20,858.50 : 28,784.73 = 12,475 : x
2. Step 2: Convert to fraction form
   20,858.50/28,784.73 = 12,475/x
3. Step 3: Cross multiply
   20,858.50x = 28,784.73 × 12,475
4. Step 4: Simplify right side
   20,858.50x = 359,089,506.75
5. Step 5: Solve for x
   x = 359,089,506.75/20,858.50
6. Step 6: Final answer
   x = 17,215.50