Finding the Fourth Proportional to 82.71, 123.19 and 78.59

Step by Step Solution

1. Step 1: Write the proportion equation
   82.71 : 123.19 = 78.59 : x
2. Step 2: Convert to fraction form
   82.71/123.19 = 78.59/x
3. Step 3: Cross multiply
   82.71x = 123.19 × 78.59
4. Step 4: Simplify right side
   82.71x = 9,681.61
5. Step 5: Solve for x
   x = 9,681.61/82.71
6. Step 6: Final answer
   x = 117.05