Finding the Fourth Proportional to 105,139.95, 145,092.12 and 64,837.59

Step by Step Solution

1. Step 1: Write the proportion equation
   105,139.95 : 145,092.12 = 64,837.59 : x
2. Step 2: Convert to fraction form
   105,139.95/145,092.12 = 64,837.59/x
3. Step 3: Cross multiply
   105,139.95x = 145,092.12 × 64,837.59
4. Step 4: Simplify right side
   105,139.95x = 9,407,423,388.79
5. Step 5: Solve for x
   x = 9,407,423,388.79/105,139.95
6. Step 6: Final answer
   x = 89,475.25