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Finding the Fourth Proportional to 855.72, 1,284.06 and 513

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Solution

The fourth proportional to 855.72, 1,284.06 and 513 is: 769.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.72 : 1,284.06 = 513 : x
  2. Step 2: Convert to fraction form
    855.72/1,284.06 = 513/x
  3. Step 3: Cross multiply
    855.72x = 1,284.06 × 513
  4. Step 4: Simplify right side
    855.72x = 658,722.78
  5. Step 5: Solve for x
    x = 658,722.78/855.72
  6. Step 6: Final answer
    x = 769.79

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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.