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Finding the Fourth Proportional to 684.42, 944.49 and 389.78

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Solution

The fourth proportional to 684.42, 944.49 and 389.78 is: 537.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.42 : 944.49 = 389.78 : x
  2. Step 2: Convert to fraction form
    684.42/944.49 = 389.78/x
  3. Step 3: Cross multiply
    684.42x = 944.49 × 389.78
  4. Step 4: Simplify right side
    684.42x = 368,143.31
  5. Step 5: Solve for x
    x = 368,143.31/684.42
  6. Step 6: Final answer
    x = 537.89

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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.