Finding the Fourth Proportional to 42,918.05, 64,364.76 and 12,935.19

Step by Step Solution

1. Step 1: Write the proportion equation
   42,918.05 : 64,364.76 = 12,935.19 : x
2. Step 2: Convert to fraction form
   42,918.05/64,364.76 = 12,935.19/x
3. Step 3: Cross multiply
   42,918.05x = 64,364.76 × 12,935.19
4. Step 4: Simplify right side
   42,918.05x = 832,570,399.90
5. Step 5: Solve for x
   x = 832,570,399.90/42,918.05
6. Step 6: Final answer
   x = 19,399.07