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Finding the Fourth Proportional to 643.50, 887.85 and 394.83

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Solution

The fourth proportional to 643.50, 887.85 and 394.83 is: 544.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.50 : 887.85 = 394.83 : x
  2. Step 2: Convert to fraction form
    643.50/887.85 = 394.83/x
  3. Step 3: Cross multiply
    643.50x = 887.85 × 394.83
  4. Step 4: Simplify right side
    643.50x = 350,549.82
  5. Step 5: Solve for x
    x = 350,549.82/643.50
  6. Step 6: Final answer
    x = 544.75

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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.