Finding the Fourth Proportional to 42,859.71, 64,290.42 and 12,875.13

Step by Step Solution

1. Step 1: Write the proportion equation
   42,859.71 : 64,290.42 = 12,875.13 : x
2. Step 2: Convert to fraction form
   42,859.71/64,290.42 = 12,875.13/x
3. Step 3: Cross multiply
   42,859.71x = 64,290.42 × 12,875.13
4. Step 4: Simplify right side
   42,859.71x = 827,747,515.25
5. Step 5: Solve for x
   x = 827,747,515.25/42,859.71
6. Step 6: Final answer
   x = 19,312.95