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Finding the Fourth Proportional to 306.78, 423.18 and 218.28

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Solution

The fourth proportional to 306.78, 423.18 and 218.28 is: 301.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    306.78 : 423.18 = 218.28 : x
  2. Step 2: Convert to fraction form
    306.78/423.18 = 218.28/x
  3. Step 3: Cross multiply
    306.78x = 423.18 × 218.28
  4. Step 4: Simplify right side
    306.78x = 92,371.73
  5. Step 5: Solve for x
    x = 92,371.73/306.78
  6. Step 6: Final answer
    x = 301.10

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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.