Finding the Fourth Proportional to 82.61, 123.71 and 58.31

Step by Step Solution

1. Step 1: Write the proportion equation
   82.61 : 123.71 = 58.31 : x
2. Step 2: Convert to fraction form
   82.61/123.71 = 58.31/x
3. Step 3: Cross multiply
   82.61x = 123.71 × 58.31
4. Step 4: Simplify right side
   82.61x = 7,212.62
5. Step 5: Solve for x
   x = 7,212.62/82.61
6. Step 6: Final answer
   x = 87.31