Finding the Fourth Proportional to 28,151.42, 42,169.72 and 13,315.36

Step by Step Solution

1. Step 1: Write the proportion equation
   28,151.42 : 42,169.72 = 13,315.36 : x
2. Step 2: Convert to fraction form
   28,151.42/42,169.72 = 13,315.36/x
3. Step 3: Cross multiply
   28,151.42x = 42,169.72 × 13,315.36
4. Step 4: Simplify right side
   28,151.42x = 561,505,002.90
5. Step 5: Solve for x
   x = 561,505,002.90/28,151.42
6. Step 6: Final answer
   x = 19,945.89