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Finding the Fourth Proportional to 639.65, 961.20 and 347.36

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Solution

The fourth proportional to 639.65, 961.20 and 347.36 is: 521.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.65 : 961.20 = 347.36 : x
  2. Step 2: Convert to fraction form
    639.65/961.20 = 347.36/x
  3. Step 3: Cross multiply
    639.65x = 961.20 × 347.36
  4. Step 4: Simplify right side
    639.65x = 333,877.63
  5. Step 5: Solve for x
    x = 333,877.63/639.65
  6. Step 6: Final answer
    x = 521.97

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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.