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Finding the Fourth Proportional to 486.76, 669.70 and 355.40

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Solution

The fourth proportional to 486.76, 669.70 and 355.40 is: 488.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.76 : 669.70 = 355.40 : x
  2. Step 2: Convert to fraction form
    486.76/669.70 = 355.40/x
  3. Step 3: Cross multiply
    486.76x = 669.70 × 355.40
  4. Step 4: Simplify right side
    486.76x = 238,011.38
  5. Step 5: Solve for x
    x = 238,011.38/486.76
  6. Step 6: Final answer
    x = 488.97

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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.