Finding the Fourth Proportional to 82.57, 123.70 and 42.02

Step by Step Solution

1. Step 1: Write the proportion equation
   82.57 : 123.70 = 42.02 : x
2. Step 2: Convert to fraction form
   82.57/123.70 = 42.02/x
3. Step 3: Cross multiply
   82.57x = 123.70 × 42.02
4. Step 4: Simplify right side
   82.57x = 5,197.81
5. Step 5: Solve for x
   x = 5,197.81/82.57
6. Step 6: Final answer
   x = 62.95