Finding the Fourth Proportional to 82.61, 123.90 and 42.00

Step by Step Solution

1. Step 1: Write the proportion equation
   82.61 : 123.90 = 42.00 : x
2. Step 2: Convert to fraction form
   82.61/123.90 = 42.00/x
3. Step 3: Cross multiply
   82.61x = 123.90 × 42.00
4. Step 4: Simplify right side
   82.61x = 5,203.60
5. Step 5: Solve for x
   x = 5,203.60/82.61
6. Step 6: Final answer
   x = 62.99