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Finding the Fourth Proportional to 643.20, 887.88 and 381.24

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Solution

The fourth proportional to 643.20, 887.88 and 381.24 is: 526.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.20 : 887.88 = 381.24 : x
  2. Step 2: Convert to fraction form
    643.20/887.88 = 381.24/x
  3. Step 3: Cross multiply
    643.20x = 887.88 × 381.24
  4. Step 4: Simplify right side
    643.20x = 338,495.37
  5. Step 5: Solve for x
    x = 338,495.37/643.20
  6. Step 6: Final answer
    x = 526.27

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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.