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Finding the Fourth Proportional to 642.91, 887.14 and 394.30

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Solution

The fourth proportional to 642.91, 887.14 and 394.30 is: 544.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.91 : 887.14 = 394.30 : x
  2. Step 2: Convert to fraction form
    642.91/887.14 = 394.30/x
  3. Step 3: Cross multiply
    642.91x = 887.14 × 394.30
  4. Step 4: Simplify right side
    642.91x = 349,799.30
  5. Step 5: Solve for x
    x = 349,799.30/642.91
  6. Step 6: Final answer
    x = 544.09

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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.