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Finding the Fourth Proportional to 639.69, 959.79 and 228.87

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Solution

The fourth proportional to 639.69, 959.79 and 228.87 is: 343.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.69 : 959.79 = 228.87 : x
  2. Step 2: Convert to fraction form
    639.69/959.79 = 228.87/x
  3. Step 3: Cross multiply
    639.69x = 959.79 × 228.87
  4. Step 4: Simplify right side
    639.69x = 219,667.14
  5. Step 5: Solve for x
    x = 219,667.14/639.69
  6. Step 6: Final answer
    x = 343.40

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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.