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Finding the Fourth Proportional to 709.90, 979.72 and 395.19

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Solution

The fourth proportional to 709.90, 979.72 and 395.19 is: 545.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.90 : 979.72 = 395.19 : x
  2. Step 2: Convert to fraction form
    709.90/979.72 = 395.19/x
  3. Step 3: Cross multiply
    709.90x = 979.72 × 395.19
  4. Step 4: Simplify right side
    709.90x = 387,174.56
  5. Step 5: Solve for x
    x = 387,174.56/709.90
  6. Step 6: Final answer
    x = 545.40

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Half scale
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Double scale
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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.