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Finding the Fourth Proportional to 643.05, 887.31 and 394.47

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Solution

The fourth proportional to 643.05, 887.31 and 394.47 is: 544.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.05 : 887.31 = 394.47 : x
  2. Step 2: Convert to fraction form
    643.05/887.31 = 394.47/x
  3. Step 3: Cross multiply
    643.05x = 887.31 × 394.47
  4. Step 4: Simplify right side
    643.05x = 350,017.18
  5. Step 5: Solve for x
    x = 350,017.18/643.05
  6. Step 6: Final answer
    x = 544.31

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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.