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Finding the Fourth Proportional to 639.67, 959.70 and 228.80

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Solution

The fourth proportional to 639.67, 959.70 and 228.80 is: 343.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.67 : 959.70 = 228.80 : x
  2. Step 2: Convert to fraction form
    639.67/959.70 = 228.80/x
  3. Step 3: Cross multiply
    639.67x = 959.70 × 228.80
  4. Step 4: Simplify right side
    639.67x = 219,579.36
  5. Step 5: Solve for x
    x = 219,579.36/639.67
  6. Step 6: Final answer
    x = 343.27

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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.