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Finding the Fourth Proportional to 489.78, 671.37 and 487.62

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Solution

The fourth proportional to 489.78, 671.37 and 487.62 is: 668.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.78 : 671.37 = 487.62 : x
  2. Step 2: Convert to fraction form
    489.78/671.37 = 487.62/x
  3. Step 3: Cross multiply
    489.78x = 671.37 × 487.62
  4. Step 4: Simplify right side
    489.78x = 327,373.44
  5. Step 5: Solve for x
    x = 327,373.44/489.78
  6. Step 6: Final answer
    x = 668.41

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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.