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Finding the Fourth Proportional to 643.28, 887.73 and 381.43

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Solution

The fourth proportional to 643.28, 887.73 and 381.43 is: 526.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.28 : 887.73 = 381.43 : x
  2. Step 2: Convert to fraction form
    643.28/887.73 = 381.43/x
  3. Step 3: Cross multiply
    643.28x = 887.73 × 381.43
  4. Step 4: Simplify right side
    643.28x = 338,602.42
  5. Step 5: Solve for x
    x = 338,602.42/643.28
  6. Step 6: Final answer
    x = 526.37

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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.