Finding the Fourth Proportional to 82.50, 113.82 and 61.78

Step by Step Solution

1. Step 1: Write the proportion equation
   82.50 : 113.82 = 61.78 : x
2. Step 2: Convert to fraction form
   82.50/113.82 = 61.78/x
3. Step 3: Cross multiply
   82.50x = 113.82 × 61.78
4. Step 4: Simplify right side
   82.50x = 7,031.80
5. Step 5: Solve for x
   x = 7,031.80/82.50
6. Step 6: Final answer
   x = 85.24