Finding the Fourth Proportional to 42,868.83, 64,279.76 and 13,278.45

Step by Step Solution

1. Step 1: Write the proportion equation
   42,868.83 : 64,279.76 = 13,278.45 : x
2. Step 2: Convert to fraction form
   42,868.83/64,279.76 = 13,278.45/x
3. Step 3: Cross multiply
   42,868.83x = 64,279.76 × 13,278.45
4. Step 4: Simplify right side
   42,868.83x = 853,535,512.78
5. Step 5: Solve for x
   x = 853,535,512.78/42,868.83
6. Step 6: Final answer
   x = 19,910.40