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Finding the Fourth Proportional to 518.40, 715.04 and 311.44

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Solution

The fourth proportional to 518.40, 715.04 and 311.44 is: 429.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.40 : 715.04 = 311.44 : x
  2. Step 2: Convert to fraction form
    518.40/715.04 = 311.44/x
  3. Step 3: Cross multiply
    518.40x = 715.04 × 311.44
  4. Step 4: Simplify right side
    518.40x = 222,692.06
  5. Step 5: Solve for x
    x = 222,692.06/518.40
  6. Step 6: Final answer
    x = 429.58

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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.