Finding the Fourth Proportional to 42,776.69, 64,172.33 and 13,189.01

Step by Step Solution

1. Step 1: Write the proportion equation
   42,776.69 : 64,172.33 = 13,189.01 : x
2. Step 2: Convert to fraction form
   42,776.69/64,172.33 = 13,189.01/x
3. Step 3: Cross multiply
   42,776.69x = 64,172.33 × 13,189.01
4. Step 4: Simplify right side
   42,776.69x = 846,369,596.58
5. Step 5: Solve for x
   x = 846,369,596.58/42,776.69
6. Step 6: Final answer
   x = 19,785.77