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Finding the Fourth Proportional to 643.23, 887.49 and 381.13

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Solution

The fourth proportional to 643.23, 887.49 and 381.13 is: 525.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.23 : 887.49 = 381.13 : x
  2. Step 2: Convert to fraction form
    643.23/887.49 = 381.13/x
  3. Step 3: Cross multiply
    643.23x = 887.49 × 381.13
  4. Step 4: Simplify right side
    643.23x = 338,246.84
  5. Step 5: Solve for x
    x = 338,246.84/643.23
  6. Step 6: Final answer
    x = 525.86

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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.