Finding the Fourth Proportional to 52,128.78, 78,207.75 and 20,519.34

Step by Step Solution

1. Step 1: Write the proportion equation
   52,128.78 : 78,207.75 = 20,519.34 : x
2. Step 2: Convert to fraction form
   52,128.78/78,207.75 = 20,519.34/x
3. Step 3: Cross multiply
   52,128.78x = 78,207.75 × 20,519.34
4. Step 4: Simplify right side
   52,128.78x = 1,604,771,412.89
5. Step 5: Solve for x
   x = 1,604,771,412.89/52,128.78
6. Step 6: Final answer
   x = 30,784.75