Finding the Fourth Proportional to 43,139.47, 64,679.18 and 19,110.72

Step by Step Solution

1. Step 1: Write the proportion equation
   43,139.47 : 64,679.18 = 19,110.72 : x
2. Step 2: Convert to fraction form
   43,139.47/64,679.18 = 19,110.72/x
3. Step 3: Cross multiply
   43,139.47x = 64,679.18 × 19,110.72
4. Step 4: Simplify right side
   43,139.47x = 1,236,065,674.92
5. Step 5: Solve for x
   x = 1,236,065,674.92/43,139.47
6. Step 6: Final answer
   x = 28,652.78