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Finding the Fourth Proportional to 643.16, 887.49 and 394.55

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Solution

The fourth proportional to 643.16, 887.49 and 394.55 is: 544.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.16 : 887.49 = 394.55 : x
  2. Step 2: Convert to fraction form
    643.16/887.49 = 394.55/x
  3. Step 3: Cross multiply
    643.16x = 887.49 × 394.55
  4. Step 4: Simplify right side
    643.16x = 350,154.74
  5. Step 5: Solve for x
    x = 350,154.74/643.16
  6. Step 6: Final answer
    x = 544.43

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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.