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Finding the Fourth Proportional to 677.66, 939.45 and 640.70

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Solution

The fourth proportional to 677.66, 939.45 and 640.70 is: 888.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    677.66 : 939.45 = 640.70 : x
  2. Step 2: Convert to fraction form
    677.66/939.45 = 640.70/x
  3. Step 3: Cross multiply
    677.66x = 939.45 × 640.70
  4. Step 4: Simplify right side
    677.66x = 601,905.62
  5. Step 5: Solve for x
    x = 601,905.62/677.66
  6. Step 6: Final answer
    x = 888.21

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.