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Finding the Fourth Proportional to 399.85, 551.63 and 289.09

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Solution

The fourth proportional to 399.85, 551.63 and 289.09 is: 398.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.85 : 551.63 = 289.09 : x
  2. Step 2: Convert to fraction form
    399.85/551.63 = 289.09/x
  3. Step 3: Cross multiply
    399.85x = 551.63 × 289.09
  4. Step 4: Simplify right side
    399.85x = 159,466.51
  5. Step 5: Solve for x
    x = 159,466.51/399.85
  6. Step 6: Final answer
    x = 398.82

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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.