Finding the Fourth Proportional to 42,787.45, 64,212.71 and 20,298.20

Step by Step Solution

1. Step 1: Write the proportion equation
   42,787.45 : 64,212.71 = 20,298.20 : x
2. Step 2: Convert to fraction form
   42,787.45/64,212.71 = 20,298.20/x
3. Step 3: Cross multiply
   42,787.45x = 64,212.71 × 20,298.20
4. Step 4: Simplify right side
   42,787.45x = 1,303,402,430.12
5. Step 5: Solve for x
   x = 1,303,402,430.12/42,787.45
6. Step 6: Final answer
   x = 30,462.26