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Finding the Fourth Proportional to 643.10, 887.69 and 381.11

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Solution

The fourth proportional to 643.10, 887.69 and 381.11 is: 526.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.10 : 887.69 = 381.11 : x
  2. Step 2: Convert to fraction form
    643.10/887.69 = 381.11/x
  3. Step 3: Cross multiply
    643.10x = 887.69 × 381.11
  4. Step 4: Simplify right side
    643.10x = 338,304.05
  5. Step 5: Solve for x
    x = 338,304.05/643.10
  6. Step 6: Final answer
    x = 526.06

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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.