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Finding the Fourth Proportional to 642.88, 887.20 and 381.06

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Solution

The fourth proportional to 642.88, 887.20 and 381.06 is: 525.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.88 : 887.20 = 381.06 : x
  2. Step 2: Convert to fraction form
    642.88/887.20 = 381.06/x
  3. Step 3: Cross multiply
    642.88x = 887.20 × 381.06
  4. Step 4: Simplify right side
    642.88x = 338,076.43
  5. Step 5: Solve for x
    x = 338,076.43/642.88
  6. Step 6: Final answer
    x = 525.88

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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.