Finding the Fourth Proportional to 42,763.78, 64,157.55 and 17,815.60

Step by Step Solution

1. Step 1: Write the proportion equation
   42,763.78 : 64,157.55 = 17,815.60 : x
2. Step 2: Convert to fraction form
   42,763.78/64,157.55 = 17,815.60/x
3. Step 3: Cross multiply
   42,763.78x = 64,157.55 × 17,815.60
4. Step 4: Simplify right side
   42,763.78x = 1,143,005,247.78
5. Step 5: Solve for x
   x = 1,143,005,247.78/42,763.78
6. Step 6: Final answer
   x = 26,728.35