Finding the Fourth Proportional to 105,663.76, 145,830.94 and 65,390.50

Step by Step Solution

1. Step 1: Write the proportion equation
   105,663.76 : 145,830.94 = 65,390.50 : x
2. Step 2: Convert to fraction form
   105,663.76/145,830.94 = 65,390.50/x
3. Step 3: Cross multiply
   105,663.76x = 145,830.94 × 65,390.50
4. Step 4: Simplify right side
   105,663.76x = 9,535,958,082.07
5. Step 5: Solve for x
   x = 9,535,958,082.07/105,663.76
6. Step 6: Final answer
   x = 90,248.14