Finding the Fourth Proportional to 105,667.06, 145,819.68 and 57,920.30

Step by Step Solution

1. Step 1: Write the proportion equation
   105,667.06 : 145,819.68 = 57,920.30 : x
2. Step 2: Convert to fraction form
   105,667.06/145,819.68 = 57,920.30/x
3. Step 3: Cross multiply
   105,667.06x = 145,819.68 × 57,920.30
4. Step 4: Simplify right side
   105,667.06x = 8,445,919,611.50
5. Step 5: Solve for x
   x = 8,445,919,611.50/105,667.06
6. Step 6: Final answer
   x = 79,929.54