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Finding the Fourth Proportional to 309.81, 426.67 and 286.72

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Solution

The fourth proportional to 309.81, 426.67 and 286.72 is: 394.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.81 : 426.67 = 286.72 : x
  2. Step 2: Convert to fraction form
    309.81/426.67 = 286.72/x
  3. Step 3: Cross multiply
    309.81x = 426.67 × 286.72
  4. Step 4: Simplify right side
    309.81x = 122,333.39
  5. Step 5: Solve for x
    x = 122,333.39/309.81
  6. Step 6: Final answer
    x = 394.87

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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.