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Finding the Fourth Proportional to 639.64, 959.57 and 200.81

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Solution

The fourth proportional to 639.64, 959.57 and 200.81 is: 301.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.64 : 959.57 = 200.81 : x
  2. Step 2: Convert to fraction form
    639.64/959.57 = 200.81/x
  3. Step 3: Cross multiply
    639.64x = 959.57 × 200.81
  4. Step 4: Simplify right side
    639.64x = 192,690.55
  5. Step 5: Solve for x
    x = 192,690.55/639.64
  6. Step 6: Final answer
    x = 301.25

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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.