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Finding the Fourth Proportional to 318.78, 477.09 and 215.64

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Solution

The fourth proportional to 318.78, 477.09 and 215.64 is: 322.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.78 : 477.09 = 215.64 : x
  2. Step 2: Convert to fraction form
    318.78/477.09 = 215.64/x
  3. Step 3: Cross multiply
    318.78x = 477.09 × 215.64
  4. Step 4: Simplify right side
    318.78x = 102,879.69
  5. Step 5: Solve for x
    x = 102,879.69/318.78
  6. Step 6: Final answer
    x = 322.73

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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.