Finding the Fourth Proportional to 128,478.18, 177,304.86 and 71,888.34

Step by Step Solution

1. Step 1: Write the proportion equation
   128,478.18 : 177,304.86 = 71,888.34 : x
2. Step 2: Convert to fraction form
   128,478.18/177,304.86 = 71,888.34/x
3. Step 3: Cross multiply
   128,478.18x = 177,304.86 × 71,888.34
4. Step 4: Simplify right side
   128,478.18x = 12,746,152,059.33
5. Step 5: Solve for x
   x = 12,746,152,059.33/128,478.18
6. Step 6: Final answer
   x = 99,208.69