Finding the Fourth Proportional to 111.60, 167.40 and 102.15

Step by Step Solution

1. Step 1: Write the proportion equation
   111.60 : 167.40 = 102.15 : x
2. Step 2: Convert to fraction form
   111.60/167.40 = 102.15/x
3. Step 3: Cross multiply
   111.60x = 167.40 × 102.15
4. Step 4: Simplify right side
   111.60x = 17,099.91
5. Step 5: Solve for x
   x = 17,099.91/111.60
6. Step 6: Final answer
   x = 153.23