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Finding the Fourth Proportional to 645.78, 969.17 and 521.00

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Solution

The fourth proportional to 645.78, 969.17 and 521.00 is: 781.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.78 : 969.17 = 521.00 : x
  2. Step 2: Convert to fraction form
    645.78/969.17 = 521.00/x
  3. Step 3: Cross multiply
    645.78x = 969.17 × 521.00
  4. Step 4: Simplify right side
    645.78x = 504,930.12
  5. Step 5: Solve for x
    x = 504,930.12/645.78
  6. Step 6: Final answer
    x = 781.89

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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.