Finding the Fourth Proportional to 105.30, 145.47 and 91.50

Step by Step Solution

1. Step 1: Write the proportion equation
   105.30 : 145.47 = 91.50 : x
2. Step 2: Convert to fraction form
   105.30/145.47 = 91.50/x
3. Step 3: Cross multiply
   105.30x = 145.47 × 91.50
4. Step 4: Simplify right side
   105.30x = 13,310.51
5. Step 5: Solve for x
   x = 13,310.51/105.30
6. Step 6: Final answer
   x = 126.41