Finding the Fourth Proportional to 143.50, 214.37 and 91.72

Step by Step Solution

1. Step 1: Write the proportion equation
   143.50 : 214.37 = 91.72 : x
2. Step 2: Convert to fraction form
   143.50/214.37 = 91.72/x
3. Step 3: Cross multiply
   143.50x = 214.37 × 91.72
4. Step 4: Simplify right side
   143.50x = 19,662.02
5. Step 5: Solve for x
   x = 19,662.02/143.50
6. Step 6: Final answer
   x = 137.02