Finding the Fourth Proportional to 100.71, 139.10 and 67.91

Step by Step Solution

1. Step 1: Write the proportion equation
   100.71 : 139.10 = 67.91 : x
2. Step 2: Convert to fraction form
   100.71/139.10 = 67.91/x
3. Step 3: Cross multiply
   100.71x = 139.10 × 67.91
4. Step 4: Simplify right side
   100.71x = 9,445.59
5. Step 5: Solve for x
   x = 9,445.59/100.71
6. Step 6: Final answer
   x = 93.79