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Finding the Fourth Proportional to 405.78, 558.18 and 339.36

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Solution

The fourth proportional to 405.78, 558.18 and 339.36 is: 466.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.78 : 558.18 = 339.36 : x
  2. Step 2: Convert to fraction form
    405.78/558.18 = 339.36/x
  3. Step 3: Cross multiply
    405.78x = 558.18 × 339.36
  4. Step 4: Simplify right side
    405.78x = 189,423.96
  5. Step 5: Solve for x
    x = 189,423.96/405.78
  6. Step 6: Final answer
    x = 466.81

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.