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Finding the Fourth Proportional to 643.12, 887.46 and 381.12

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Solution

The fourth proportional to 643.12, 887.46 and 381.12 is: 525.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.12 : 887.46 = 381.12 : x
  2. Step 2: Convert to fraction form
    643.12/887.46 = 381.12/x
  3. Step 3: Cross multiply
    643.12x = 887.46 × 381.12
  4. Step 4: Simplify right side
    643.12x = 338,228.76
  5. Step 5: Solve for x
    x = 338,228.76/643.12
  6. Step 6: Final answer
    x = 525.92

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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.