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Finding the Fourth Proportional to 322.78, 445.73 and 287.81

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Solution

The fourth proportional to 322.78, 445.73 and 287.81 is: 397.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    322.78 : 445.73 = 287.81 : x
  2. Step 2: Convert to fraction form
    322.78/445.73 = 287.81/x
  3. Step 3: Cross multiply
    322.78x = 445.73 × 287.81
  4. Step 4: Simplify right side
    322.78x = 128,285.55
  5. Step 5: Solve for x
    x = 128,285.55/322.78
  6. Step 6: Final answer
    x = 397.44

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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.