Finding the Fourth Proportional to 42,970.29, 64,458.53 and 17,985.20

Step by Step Solution

1. Step 1: Write the proportion equation
   42,970.29 : 64,458.53 = 17,985.20 : x
2. Step 2: Convert to fraction form
   42,970.29/64,458.53 = 17,985.20/x
3. Step 3: Cross multiply
   42,970.29x = 64,458.53 × 17,985.20
4. Step 4: Simplify right side
   42,970.29x = 1,159,299,141.54
5. Step 5: Solve for x
   x = 1,159,299,141.54/42,970.29
6. Step 6: Final answer
   x = 26,979.09