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Finding the Fourth Proportional to 779.92, 1,169.56 and 389.78

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Solution

The fourth proportional to 779.92, 1,169.56 and 389.78 is: 584.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    779.92 : 1,169.56 = 389.78 : x
  2. Step 2: Convert to fraction form
    779.92/1,169.56 = 389.78/x
  3. Step 3: Cross multiply
    779.92x = 1,169.56 × 389.78
  4. Step 4: Simplify right side
    779.92x = 455,864.27
  5. Step 5: Solve for x
    x = 455,864.27/779.92
  6. Step 6: Final answer
    x = 584.50

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Half scale
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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.