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Finding the Fourth Proportional to 865.71, 1,298.58 and 378.65

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Solution

The fourth proportional to 865.71, 1,298.58 and 378.65 is: 567.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.71 : 1,298.58 = 378.65 : x
  2. Step 2: Convert to fraction form
    865.71/1,298.58 = 378.65/x
  3. Step 3: Cross multiply
    865.71x = 1,298.58 × 378.65
  4. Step 4: Simplify right side
    865.71x = 491,707.62
  5. Step 5: Solve for x
    x = 491,707.62/865.71
  6. Step 6: Final answer
    x = 567.98

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Double scale
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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.