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Finding the Fourth Proportional to 665.27, 996.36 and 642.20

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Solution

The fourth proportional to 665.27, 996.36 and 642.20 is: 961.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.27 : 996.36 = 642.20 : x
  2. Step 2: Convert to fraction form
    665.27/996.36 = 642.20/x
  3. Step 3: Cross multiply
    665.27x = 996.36 × 642.20
  4. Step 4: Simplify right side
    665.27x = 639,862.39
  5. Step 5: Solve for x
    x = 639,862.39/665.27
  6. Step 6: Final answer
    x = 961.81

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.