Finding the Fourth Proportional to 100.79, 151.17 and 83.78

Step by Step Solution

1. Step 1: Write the proportion equation
   100.79 : 151.17 = 83.78 : x
2. Step 2: Convert to fraction form
   100.79/151.17 = 83.78/x
3. Step 3: Cross multiply
   100.79x = 151.17 × 83.78
4. Step 4: Simplify right side
   100.79x = 12,665.02
5. Step 5: Solve for x
   x = 12,665.02/100.79
6. Step 6: Final answer
   x = 125.66