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Finding the Fourth Proportional to 643.85, 961.86 and 410.89

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Solution

The fourth proportional to 643.85, 961.86 and 410.89 is: 613.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.85 : 961.86 = 410.89 : x
  2. Step 2: Convert to fraction form
    643.85/961.86 = 410.89/x
  3. Step 3: Cross multiply
    643.85x = 961.86 × 410.89
  4. Step 4: Simplify right side
    643.85x = 395,216.25
  5. Step 5: Solve for x
    x = 395,216.25/643.85
  6. Step 6: Final answer
    x = 613.83

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.