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Finding the Fourth Proportional to 861.23, 1,291.83 and 211.97

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Solution

The fourth proportional to 861.23, 1,291.83 and 211.97 is: 317.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    861.23 : 1,291.83 = 211.97 : x
  2. Step 2: Convert to fraction form
    861.23/1,291.83 = 211.97/x
  3. Step 3: Cross multiply
    861.23x = 1,291.83 × 211.97
  4. Step 4: Simplify right side
    861.23x = 273,831.64
  5. Step 5: Solve for x
    x = 273,831.64/861.23
  6. Step 6: Final answer
    x = 317.95

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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.