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Finding the Fourth Proportional to 667.38, 920.91 and 387.57

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Solution

The fourth proportional to 667.38, 920.91 and 387.57 is: 534.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    667.38 : 920.91 = 387.57 : x
  2. Step 2: Convert to fraction form
    667.38/920.91 = 387.57/x
  3. Step 3: Cross multiply
    667.38x = 920.91 × 387.57
  4. Step 4: Simplify right side
    667.38x = 356,917.09
  5. Step 5: Solve for x
    x = 356,917.09/667.38
  6. Step 6: Final answer
    x = 534.80

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.