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Finding the Fourth Proportional to 643.65, 887.97 and 394.88

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Solution

The fourth proportional to 643.65, 887.97 and 394.88 is: 544.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.65 : 887.97 = 394.88 : x
  2. Step 2: Convert to fraction form
    643.65/887.97 = 394.88/x
  3. Step 3: Cross multiply
    643.65x = 887.97 × 394.88
  4. Step 4: Simplify right side
    643.65x = 350,637.15
  5. Step 5: Solve for x
    x = 350,637.15/643.65
  6. Step 6: Final answer
    x = 544.76

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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.