Finding the Fourth Proportional to 42,802.70, 64,210.89 and 13,213.58

Step by Step Solution

1. Step 1: Write the proportion equation
   42,802.70 : 64,210.89 = 13,213.58 : x
2. Step 2: Convert to fraction form
   42,802.70/64,210.89 = 13,213.58/x
3. Step 3: Cross multiply
   42,802.70x = 64,210.89 × 13,213.58
4. Step 4: Simplify right side
   42,802.70x = 848,455,731.89
5. Step 5: Solve for x
   x = 848,455,731.89/42,802.70
6. Step 6: Final answer
   x = 19,822.48