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Finding the Fourth Proportional to 677.68, 1,009.82 and 639.28

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Solution

The fourth proportional to 677.68, 1,009.82 and 639.28 is: 952.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    677.68 : 1,009.82 = 639.28 : x
  2. Step 2: Convert to fraction form
    677.68/1,009.82 = 639.28/x
  3. Step 3: Cross multiply
    677.68x = 1,009.82 × 639.28
  4. Step 4: Simplify right side
    677.68x = 645,557.73
  5. Step 5: Solve for x
    x = 645,557.73/677.68
  6. Step 6: Final answer
    x = 952.60

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.