Finding the Fourth Proportional to 42,867.38, 64,317.93 and 13,287.50

Step by Step Solution

1. Step 1: Write the proportion equation
   42,867.38 : 64,317.93 = 13,287.50 : x
2. Step 2: Convert to fraction form
   42,867.38/64,317.93 = 13,287.50/x
3. Step 3: Cross multiply
   42,867.38x = 64,317.93 × 13,287.50
4. Step 4: Simplify right side
   42,867.38x = 854,624,494.88
5. Step 5: Solve for x
   x = 854,624,494.88/42,867.38
6. Step 6: Final answer
   x = 19,936.48