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Finding the Fourth Proportional to 318.85, 439.81 and 284.11

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Solution

The fourth proportional to 318.85, 439.81 and 284.11 is: 391.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.85 : 439.81 = 284.11 : x
  2. Step 2: Convert to fraction form
    318.85/439.81 = 284.11/x
  3. Step 3: Cross multiply
    318.85x = 439.81 × 284.11
  4. Step 4: Simplify right side
    318.85x = 124,954.42
  5. Step 5: Solve for x
    x = 124,954.42/318.85
  6. Step 6: Final answer
    x = 391.89

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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.