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Finding the Fourth Proportional to 643.32, 887.79 and 355.88

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Solution

The fourth proportional to 643.32, 887.79 and 355.88 is: 491.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.32 : 887.79 = 355.88 : x
  2. Step 2: Convert to fraction form
    643.32/887.79 = 355.88/x
  3. Step 3: Cross multiply
    643.32x = 887.79 × 355.88
  4. Step 4: Simplify right side
    643.32x = 315,942.27
  5. Step 5: Solve for x
    x = 315,942.27/643.32
  6. Step 6: Final answer
    x = 491.11

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.