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Finding the Fourth Proportional to 279.39, 418.78 and 142.30

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Solution

The fourth proportional to 279.39, 418.78 and 142.30 is: 213.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.39 : 418.78 = 142.30 : x
  2. Step 2: Convert to fraction form
    279.39/418.78 = 142.30/x
  3. Step 3: Cross multiply
    279.39x = 418.78 × 142.30
  4. Step 4: Simplify right side
    279.39x = 59,590.99
  5. Step 5: Solve for x
    x = 59,590.99/279.39
  6. Step 6: Final answer
    x = 213.29

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.