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Finding the Fourth Proportional to 643.38, 887.81 and 394.59

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Solution

The fourth proportional to 643.38, 887.81 and 394.59 is: 544.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.38 : 887.81 = 394.59 : x
  2. Step 2: Convert to fraction form
    643.38/887.81 = 394.59/x
  3. Step 3: Cross multiply
    643.38x = 887.81 × 394.59
  4. Step 4: Simplify right side
    643.38x = 350,320.95
  5. Step 5: Solve for x
    x = 350,320.95/643.38
  6. Step 6: Final answer
    x = 544.50

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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.