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Finding the Fourth Proportional to 640.84, 876.80 and 638.44

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Solution

The fourth proportional to 640.84, 876.80 and 638.44 is: 873.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.84 : 876.80 = 638.44 : x
  2. Step 2: Convert to fraction form
    640.84/876.80 = 638.44/x
  3. Step 3: Cross multiply
    640.84x = 876.80 × 638.44
  4. Step 4: Simplify right side
    640.84x = 559,784.19
  5. Step 5: Solve for x
    x = 559,784.19/640.84
  6. Step 6: Final answer
    x = 873.52

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.