Finding the Fourth Proportional to 71.22, 106.86 and 53.98

Step by Step Solution

1. Step 1: Write the proportion equation
   71.22 : 106.86 = 53.98 : x
2. Step 2: Convert to fraction form
   71.22/106.86 = 53.98/x
3. Step 3: Cross multiply
   71.22x = 106.86 × 53.98
4. Step 4: Simplify right side
   71.22x = 5,767.50
5. Step 5: Solve for x
   x = 5,767.50/71.22
6. Step 6: Final answer
   x = 80.98