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Finding the Fourth Proportional to 639.72, 959.16 and 228.65

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Solution

The fourth proportional to 639.72, 959.16 and 228.65 is: 342.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.72 : 959.16 = 228.65 : x
  2. Step 2: Convert to fraction form
    639.72/959.16 = 228.65/x
  3. Step 3: Cross multiply
    639.72x = 959.16 × 228.65
  4. Step 4: Simplify right side
    639.72x = 219,307.14
  5. Step 5: Solve for x
    x = 219,307.14/639.72
  6. Step 6: Final answer
    x = 342.82

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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.