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Finding the Fourth Proportional to 643.56, 888.60 and 395.22

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Solution

The fourth proportional to 643.56, 888.60 and 395.22 is: 545.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.56 : 888.60 = 395.22 : x
  2. Step 2: Convert to fraction form
    643.56/888.60 = 395.22/x
  3. Step 3: Cross multiply
    643.56x = 888.60 × 395.22
  4. Step 4: Simplify right side
    643.56x = 351,192.49
  5. Step 5: Solve for x
    x = 351,192.49/643.56
  6. Step 6: Final answer
    x = 545.70

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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.