Finding the Fourth Proportional to 42,927.42, 64,390.81 and 13,345.20

Step by Step Solution

1. Step 1: Write the proportion equation
   42,927.42 : 64,390.81 = 13,345.20 : x
2. Step 2: Convert to fraction form
   42,927.42/64,390.81 = 13,345.20/x
3. Step 3: Cross multiply
   42,927.42x = 64,390.81 × 13,345.20
4. Step 4: Simplify right side
   42,927.42x = 859,308,237.61
5. Step 5: Solve for x
   x = 859,308,237.61/42,927.42
6. Step 6: Final answer
   x = 20,017.70