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Finding the Fourth Proportional to 639.48, 958.70 and 228.39

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Solution

The fourth proportional to 639.48, 958.70 and 228.39 is: 342.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.48 : 958.70 = 228.39 : x
  2. Step 2: Convert to fraction form
    639.48/958.70 = 228.39/x
  3. Step 3: Cross multiply
    639.48x = 958.70 × 228.39
  4. Step 4: Simplify right side
    639.48x = 218,956.35
  5. Step 5: Solve for x
    x = 218,956.35/639.48
  6. Step 6: Final answer
    x = 342.40

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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.