Finding the Fourth Proportional to 82.91, 123.35 and 82.60

Step by Step Solution

1. Step 1: Write the proportion equation
   82.91 : 123.35 = 82.60 : x
2. Step 2: Convert to fraction form
   82.91/123.35 = 82.60/x
3. Step 3: Cross multiply
   82.91x = 123.35 × 82.60
4. Step 4: Simplify right side
   82.91x = 10,188.71
5. Step 5: Solve for x
   x = 10,188.71/82.91
6. Step 6: Final answer
   x = 122.89