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Finding the Fourth Proportional to 487.12, 672 and 280

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Solution

The fourth proportional to 487.12, 672 and 280 is: 386.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.12 : 672 = 280 : x
  2. Step 2: Convert to fraction form
    487.12/672 = 280/x
  3. Step 3: Cross multiply
    487.12x = 672 × 280
  4. Step 4: Simplify right side
    487.12x = 188,160
  5. Step 5: Solve for x
    x = 188,160/487.12
  6. Step 6: Final answer
    x = 386.27

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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.