Finding the Fourth Proportional to 42,799.38, 64,175.76 and 13,211.70

Step by Step Solution

1. Step 1: Write the proportion equation
   42,799.38 : 64,175.76 = 13,211.70 : x
2. Step 2: Convert to fraction form
   42,799.38/64,175.76 = 13,211.70/x
3. Step 3: Cross multiply
   42,799.38x = 64,175.76 × 13,211.70
4. Step 4: Simplify right side
   42,799.38x = 847,870,888.39
5. Step 5: Solve for x
   x = 847,870,888.39/42,799.38
6. Step 6: Final answer
   x = 19,810.35