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Finding the Fourth Proportional to 399.09, 551.09 and 306.75

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Solution

The fourth proportional to 399.09, 551.09 and 306.75 is: 423.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.09 : 551.09 = 306.75 : x
  2. Step 2: Convert to fraction form
    399.09/551.09 = 306.75/x
  3. Step 3: Cross multiply
    399.09x = 551.09 × 306.75
  4. Step 4: Simplify right side
    399.09x = 169,046.86
  5. Step 5: Solve for x
    x = 169,046.86/399.09
  6. Step 6: Final answer
    x = 423.58

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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.