Finding the Fourth Proportional to 100.02, 138.06 and 88.50

Step by Step Solution

1. Step 1: Write the proportion equation
   100.02 : 138.06 = 88.50 : x
2. Step 2: Convert to fraction form
   100.02/138.06 = 88.50/x
3. Step 3: Cross multiply
   100.02x = 138.06 × 88.50
4. Step 4: Simplify right side
   100.02x = 12,218.31
5. Step 5: Solve for x
   x = 12,218.31/100.02
6. Step 6: Final answer
   x = 122.16