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Finding the Fourth Proportional to 859.72, 1,289.60 and 517

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Solution

The fourth proportional to 859.72, 1,289.60 and 517 is: 775.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.72 : 1,289.60 = 517 : x
  2. Step 2: Convert to fraction form
    859.72/1,289.60 = 517/x
  3. Step 3: Cross multiply
    859.72x = 1,289.60 × 517
  4. Step 4: Simplify right side
    859.72x = 666,723.20
  5. Step 5: Solve for x
    x = 666,723.20/859.72
  6. Step 6: Final answer
    x = 775.51

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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.