Finding the Fourth Proportional to 42,779.52, 64,171.10 and 13,196.70

Step by Step Solution

1. Step 1: Write the proportion equation
   42,779.52 : 64,171.10 = 13,196.70 : x
2. Step 2: Convert to fraction form
   42,779.52/64,171.10 = 13,196.70/x
3. Step 3: Cross multiply
   42,779.52x = 64,171.10 × 13,196.70
4. Step 4: Simplify right side
   42,779.52x = 846,846,788.36
5. Step 5: Solve for x
   x = 846,846,788.36/42,779.52
6. Step 6: Final answer
   x = 19,795.61