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Finding the Fourth Proportional to 643.05, 887.42 and 394.50

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Solution

The fourth proportional to 643.05, 887.42 and 394.50 is: 544.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.05 : 887.42 = 394.50 : x
  2. Step 2: Convert to fraction form
    643.05/887.42 = 394.50/x
  3. Step 3: Cross multiply
    643.05x = 887.42 × 394.50
  4. Step 4: Simplify right side
    643.05x = 350,087.19
  5. Step 5: Solve for x
    x = 350,087.19/643.05
  6. Step 6: Final answer
    x = 544.42

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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.