Finding the Fourth Proportional to 1,379.34, 2,069.15 and 405.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.34 : 2,069.15 = 405.59 : x
2. Step 2: Convert to fraction form
   1,379.34/2,069.15 = 405.59/x
3. Step 3: Cross multiply
   1,379.34x = 2,069.15 × 405.59
4. Step 4: Simplify right side
   1,379.34x = 839,214.17
5. Step 5: Solve for x
   x = 839,214.17/1,379.34
6. Step 6: Final answer
   x = 608.42