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Finding the Fourth Proportional to 318.78, 439.17 and 303.15

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Solution

The fourth proportional to 318.78, 439.17 and 303.15 is: 417.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.78 : 439.17 = 303.15 : x
  2. Step 2: Convert to fraction form
    318.78/439.17 = 303.15/x
  3. Step 3: Cross multiply
    318.78x = 439.17 × 303.15
  4. Step 4: Simplify right side
    318.78x = 133,134.39
  5. Step 5: Solve for x
    x = 133,134.39/318.78
  6. Step 6: Final answer
    x = 417.64

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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.