Finding the Fourth Proportional to 42,836.19, 64,260.42 and 13,256.34

Step by Step Solution

1. Step 1: Write the proportion equation
   42,836.19 : 64,260.42 = 13,256.34 : x
2. Step 2: Convert to fraction form
   42,836.19/64,260.42 = 13,256.34/x
3. Step 3: Cross multiply
   42,836.19x = 64,260.42 × 13,256.34
4. Step 4: Simplify right side
   42,836.19x = 851,857,654.76
5. Step 5: Solve for x
   x = 851,857,654.76/42,836.19
6. Step 6: Final answer
   x = 19,886.40