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Finding the Fourth Proportional to 643.21, 964.05 and 252.75

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Solution

The fourth proportional to 643.21, 964.05 and 252.75 is: 378.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.21 : 964.05 = 252.75 : x
  2. Step 2: Convert to fraction form
    643.21/964.05 = 252.75/x
  3. Step 3: Cross multiply
    643.21x = 964.05 × 252.75
  4. Step 4: Simplify right side
    643.21x = 243,663.64
  5. Step 5: Solve for x
    x = 243,663.64/643.21
  6. Step 6: Final answer
    x = 378.82

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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.