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Finding the Fourth Proportional to 643.40, 965.08 and 187.40

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Solution

The fourth proportional to 643.40, 965.08 and 187.40 is: 281.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.40 : 965.08 = 187.40 : x
  2. Step 2: Convert to fraction form
    643.40/965.08 = 187.40/x
  3. Step 3: Cross multiply
    643.40x = 965.08 × 187.40
  4. Step 4: Simplify right side
    643.40x = 180,855.99
  5. Step 5: Solve for x
    x = 180,855.99/643.40
  6. Step 6: Final answer
    x = 281.09

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Double scale
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Similar ratio
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1.5x scale

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.