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Finding the Fourth Proportional to 639.26, 958.90 and 228.40

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Solution

The fourth proportional to 639.26, 958.90 and 228.40 is: 342.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.26 : 958.90 = 228.40 : x
  2. Step 2: Convert to fraction form
    639.26/958.90 = 228.40/x
  3. Step 3: Cross multiply
    639.26x = 958.90 × 228.40
  4. Step 4: Simplify right side
    639.26x = 219,012.76
  5. Step 5: Solve for x
    x = 219,012.76/639.26
  6. Step 6: Final answer
    x = 342.60

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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.