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Finding the Fourth Proportional to 643.78, 965.49 and 205.03

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Solution

The fourth proportional to 643.78, 965.49 and 205.03 is: 307.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.78 : 965.49 = 205.03 : x
  2. Step 2: Convert to fraction form
    643.78/965.49 = 205.03/x
  3. Step 3: Cross multiply
    643.78x = 965.49 × 205.03
  4. Step 4: Simplify right side
    643.78x = 197,954.41
  5. Step 5: Solve for x
    x = 197,954.41/643.78
  6. Step 6: Final answer
    x = 307.49

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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.