Finding the Fourth Proportional to 42,815.21, 64,199.23 and 13,224.83

Step by Step Solution

1. Step 1: Write the proportion equation
   42,815.21 : 64,199.23 = 13,224.83 : x
2. Step 2: Convert to fraction form
   42,815.21/64,199.23 = 13,224.83/x
3. Step 3: Cross multiply
   42,815.21x = 64,199.23 × 13,224.83
4. Step 4: Simplify right side
   42,815.21x = 849,023,548.82
5. Step 5: Solve for x
   x = 849,023,548.82/42,815.21
6. Step 6: Final answer
   x = 19,829.95