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Finding the Fourth Proportional to 639.47, 959.15 and 177.21

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Solution

The fourth proportional to 639.47, 959.15 and 177.21 is: 265.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.47 : 959.15 = 177.21 : x
  2. Step 2: Convert to fraction form
    639.47/959.15 = 177.21/x
  3. Step 3: Cross multiply
    639.47x = 959.15 × 177.21
  4. Step 4: Simplify right side
    639.47x = 169,970.42
  5. Step 5: Solve for x
    x = 169,970.42/639.47
  6. Step 6: Final answer
    x = 265.80

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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.