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Finding the Fourth Proportional to 643.76, 888.46 and 394.99

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Solution

The fourth proportional to 643.76, 888.46 and 394.99 is: 545.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.76 : 888.46 = 394.99 : x
  2. Step 2: Convert to fraction form
    643.76/888.46 = 394.99/x
  3. Step 3: Cross multiply
    643.76x = 888.46 × 394.99
  4. Step 4: Simplify right side
    643.76x = 350,929.61
  5. Step 5: Solve for x
    x = 350,929.61/643.76
  6. Step 6: Final answer
    x = 545.13

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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.