Finding the Fourth Proportional to 42,706.89, 64,099.71 and 21,661.70

Step by Step Solution

1. Step 1: Write the proportion equation
   42,706.89 : 64,099.71 = 21,661.70 : x
2. Step 2: Convert to fraction form
   42,706.89/64,099.71 = 21,661.70/x
3. Step 3: Cross multiply
   42,706.89x = 64,099.71 × 21,661.70
4. Step 4: Simplify right side
   42,706.89x = 1,388,508,367.61
5. Step 5: Solve for x
   x = 1,388,508,367.61/42,706.89
6. Step 6: Final answer
   x = 32,512.51