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Finding the Fourth Proportional to 639.20, 953.68 and 569.90

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Solution

The fourth proportional to 639.20, 953.68 and 569.90 is: 850.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.20 : 953.68 = 569.90 : x
  2. Step 2: Convert to fraction form
    639.20/953.68 = 569.90/x
  3. Step 3: Cross multiply
    639.20x = 953.68 × 569.90
  4. Step 4: Simplify right side
    639.20x = 543,502.23
  5. Step 5: Solve for x
    x = 543,502.23/639.20
  6. Step 6: Final answer
    x = 850.29

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.