Finding the Fourth Proportional to 129,136, 178,217.40 and 78,844.72

Step by Step Solution

1. Step 1: Write the proportion equation
   129,136 : 178,217.40 = 78,844.72 : x
2. Step 2: Convert to fraction form
   129,136/178,217.40 = 78,844.72/x
3. Step 3: Cross multiply
   129,136x = 178,217.40 × 78,844.72
4. Step 4: Simplify right side
   129,136x = 14,051,501,002.13
5. Step 5: Solve for x
   x = 14,051,501,002.13/129,136
6. Step 6: Final answer
   x = 108,811.65