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Finding the Fourth Proportional to 865.49, 1,298.68 and 378.42

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Solution

The fourth proportional to 865.49, 1,298.68 and 378.42 is: 567.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.49 : 1,298.68 = 378.42 : x
  2. Step 2: Convert to fraction form
    865.49/1,298.68 = 378.42/x
  3. Step 3: Cross multiply
    865.49x = 1,298.68 × 378.42
  4. Step 4: Simplify right side
    865.49x = 491,450.10
  5. Step 5: Solve for x
    x = 491,450.10/865.49
  6. Step 6: Final answer
    x = 567.83

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Double scale
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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.