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Finding the Fourth Proportional to 487.38, 672.28 and 321.31

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Solution

The fourth proportional to 487.38, 672.28 and 321.31 is: 443.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.38 : 672.28 = 321.31 : x
  2. Step 2: Convert to fraction form
    487.38/672.28 = 321.31/x
  3. Step 3: Cross multiply
    487.38x = 672.28 × 321.31
  4. Step 4: Simplify right side
    487.38x = 216,007.80
  5. Step 5: Solve for x
    x = 216,007.80/487.38
  6. Step 6: Final answer
    x = 443.20

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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.