Finding the Fourth Proportional to 156.71, 215.10 and 142.81

Step by Step Solution

1. Step 1: Write the proportion equation
   156.71 : 215.10 = 142.81 : x
2. Step 2: Convert to fraction form
   156.71/215.10 = 142.81/x
3. Step 3: Cross multiply
   156.71x = 215.10 × 142.81
4. Step 4: Simplify right side
   156.71x = 30,717.89
5. Step 5: Solve for x
   x = 30,717.89/156.71
6. Step 6: Final answer
   x = 196.01