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Finding the Fourth Proportional to 489.36, 669.46 and 487.28

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Solution

The fourth proportional to 489.36, 669.46 and 487.28 is: 666.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.36 : 669.46 = 487.28 : x
  2. Step 2: Convert to fraction form
    489.36/669.46 = 487.28/x
  3. Step 3: Cross multiply
    489.36x = 669.46 × 487.28
  4. Step 4: Simplify right side
    489.36x = 326,214.47
  5. Step 5: Solve for x
    x = 326,214.47/489.36
  6. Step 6: Final answer
    x = 666.61

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.