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Finding the Fourth Proportional to 643.81, 888.26 and 394.87

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Solution

The fourth proportional to 643.81, 888.26 and 394.87 is: 544.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.81 : 888.26 = 394.87 : x
  2. Step 2: Convert to fraction form
    643.81/888.26 = 394.87/x
  3. Step 3: Cross multiply
    643.81x = 888.26 × 394.87
  4. Step 4: Simplify right side
    643.81x = 350,747.23
  5. Step 5: Solve for x
    x = 350,747.23/643.81
  6. Step 6: Final answer
    x = 544.80

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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.