Finding the Fourth Proportional to 100,915, 139,030.86 and 79,686.52

Step by Step Solution

1. Step 1: Write the proportion equation
   100,915 : 139,030.86 = 79,686.52 : x
2. Step 2: Convert to fraction form
   100,915/139,030.86 = 79,686.52/x
3. Step 3: Cross multiply
   100,915x = 139,030.86 × 79,686.52
4. Step 4: Simplify right side
   100,915x = 11,078,885,406.01
5. Step 5: Solve for x
   x = 11,078,885,406.01/100,915
6. Step 6: Final answer
   x = 109,784.33