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Finding the Fourth Proportional to 643.57, 887.81 and 394.45

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Solution

The fourth proportional to 643.57, 887.81 and 394.45 is: 544.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.57 : 887.81 = 394.45 : x
  2. Step 2: Convert to fraction form
    643.57/887.81 = 394.45/x
  3. Step 3: Cross multiply
    643.57x = 887.81 × 394.45
  4. Step 4: Simplify right side
    643.57x = 350,192.46
  5. Step 5: Solve for x
    x = 350,192.46/643.57
  6. Step 6: Final answer
    x = 544.14

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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.