Finding the Fourth Proportional to 105,556.21, 145,667.62 and 57,809.54

Step by Step Solution

1. Step 1: Write the proportion equation
   105,556.21 : 145,667.62 = 57,809.54 : x
2. Step 2: Convert to fraction form
   105,556.21/145,667.62 = 57,809.54/x
3. Step 3: Cross multiply
   105,556.21x = 145,667.62 × 57,809.54
4. Step 4: Simplify right side
   105,556.21x = 8,420,978,105.09
5. Step 5: Solve for x
   x = 8,420,978,105.09/105,556.21
6. Step 6: Final answer
   x = 79,777.20