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Finding the Fourth Proportional to 498.21, 689.29 and 489.48

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Solution

The fourth proportional to 498.21, 689.29 and 489.48 is: 677.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.21 : 689.29 = 489.48 : x
  2. Step 2: Convert to fraction form
    498.21/689.29 = 489.48/x
  3. Step 3: Cross multiply
    498.21x = 689.29 × 489.48
  4. Step 4: Simplify right side
    498.21x = 337,393.67
  5. Step 5: Solve for x
    x = 337,393.67/498.21
  6. Step 6: Final answer
    x = 677.21

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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.