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Finding the Fourth Proportional to 643.70, 965.55 and 355.70

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Solution

The fourth proportional to 643.70, 965.55 and 355.70 is: 533.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.70 : 965.55 = 355.70 : x
  2. Step 2: Convert to fraction form
    643.70/965.55 = 355.70/x
  3. Step 3: Cross multiply
    643.70x = 965.55 × 355.70
  4. Step 4: Simplify right side
    643.70x = 343,446.14
  5. Step 5: Solve for x
    x = 343,446.14/643.70
  6. Step 6: Final answer
    x = 533.55

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Double scale
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Similar ratio
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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.