Finding the Fourth Proportional to 42,915.39, 64,373.12 and 13,333.25

Step by Step Solution

1. Step 1: Write the proportion equation
   42,915.39 : 64,373.12 = 13,333.25 : x
2. Step 2: Convert to fraction form
   42,915.39/64,373.12 = 13,333.25/x
3. Step 3: Cross multiply
   42,915.39x = 64,373.12 × 13,333.25
4. Step 4: Simplify right side
   42,915.39x = 858,302,513.71
5. Step 5: Solve for x
   x = 858,302,513.71/42,915.39
6. Step 6: Final answer
   x = 19,999.88