Finding the Fourth Proportional to 128,338.65, 177,101.51 and 70,978.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,338.65 : 177,101.51 = 70,978.50 : x
2. Step 2: Convert to fraction form
   128,338.65/177,101.51 = 70,978.50/x
3. Step 3: Cross multiply
   128,338.65x = 177,101.51 × 70,978.50
4. Step 4: Simplify right side
   128,338.65x = 12,570,399,172.64
5. Step 5: Solve for x
   x = 12,570,399,172.64/128,338.65
6. Step 6: Final answer
   x = 97,947.10