Finding the Fourth Proportional to 156.42, 215.82 and 117.72

Step by Step Solution

1. Step 1: Write the proportion equation
   156.42 : 215.82 = 117.72 : x
2. Step 2: Convert to fraction form
   156.42/215.82 = 117.72/x
3. Step 3: Cross multiply
   156.42x = 215.82 × 117.72
4. Step 4: Simplify right side
   156.42x = 25,406.33
5. Step 5: Solve for x
   x = 25,406.33/156.42
6. Step 6: Final answer
   x = 162.42