Finding the Fourth Proportional to 42,939.82, 64,402.80 and 11,767.78

Step by Step Solution

1. Step 1: Write the proportion equation
   42,939.82 : 64,402.80 = 11,767.78 : x
2. Step 2: Convert to fraction form
   42,939.82/64,402.80 = 11,767.78/x
3. Step 3: Cross multiply
   42,939.82x = 64,402.80 × 11,767.78
4. Step 4: Simplify right side
   42,939.82x = 757,877,981.78
5. Step 5: Solve for x
   x = 757,877,981.78/42,939.82
6. Step 6: Final answer
   x = 17,649.77