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Finding the Fourth Proportional to 643.91, 888.35 and 395.10

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Solution

The fourth proportional to 643.91, 888.35 and 395.10 is: 545.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.91 : 888.35 = 395.10 : x
  2. Step 2: Convert to fraction form
    643.91/888.35 = 395.10/x
  3. Step 3: Cross multiply
    643.91x = 888.35 × 395.10
  4. Step 4: Simplify right side
    643.91x = 350,985.11
  5. Step 5: Solve for x
    x = 350,985.11/643.91
  6. Step 6: Final answer
    x = 545.09

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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.