Finding the Fourth Proportional to 42,878.39, 64,323.80 and 13,298.60

Step by Step Solution

1. Step 1: Write the proportion equation
   42,878.39 : 64,323.80 = 13,298.60 : x
2. Step 2: Convert to fraction form
   42,878.39/64,323.80 = 13,298.60/x
3. Step 3: Cross multiply
   42,878.39x = 64,323.80 × 13,298.60
4. Step 4: Simplify right side
   42,878.39x = 855,416,098.57
5. Step 5: Solve for x
   x = 855,416,098.57/42,878.39
6. Step 6: Final answer
   x = 19,949.82