Finding the Fourth Proportional to 109,915.12, 164,817.24 and 78,307.12

Step by Step Solution

1. Step 1: Write the proportion equation
   109,915.12 : 164,817.24 = 78,307.12 : x
2. Step 2: Convert to fraction form
   109,915.12/164,817.24 = 78,307.12/x
3. Step 3: Cross multiply
   109,915.12x = 164,817.24 × 78,307.12
4. Step 4: Simplify right side
   109,915.12x = 12,906,363,390.75
5. Step 5: Solve for x
   x = 12,906,363,390.75/109,915.12
6. Step 6: Final answer
   x = 117,421.18