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Finding the Fourth Proportional to 486.87, 672.09 and 287.64

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Solution

The fourth proportional to 486.87, 672.09 and 287.64 is: 397.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.87 : 672.09 = 287.64 : x
  2. Step 2: Convert to fraction form
    486.87/672.09 = 287.64/x
  3. Step 3: Cross multiply
    486.87x = 672.09 × 287.64
  4. Step 4: Simplify right side
    486.87x = 193,319.97
  5. Step 5: Solve for x
    x = 193,319.97/486.87
  6. Step 6: Final answer
    x = 397.07

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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.