Finding the Fourth Proportional to 83.55, 124.77 and 83.15

Step by Step Solution

1. Step 1: Write the proportion equation
   83.55 : 124.77 = 83.15 : x
2. Step 2: Convert to fraction form
   83.55/124.77 = 83.15/x
3. Step 3: Cross multiply
   83.55x = 124.77 × 83.15
4. Step 4: Simplify right side
   83.55x = 10,374.00
5. Step 5: Solve for x
   x = 10,374.00/83.55
6. Step 6: Final answer
   x = 124.17